diff --git a/Sources/ConnectionHandlerExample/ConnectionHandlerExample.swift b/Sources/ConnectionHandlerExample/ConnectionHandlerExample.swift
index ed89ad0..5243493 100644
--- a/Sources/ConnectionHandlerExample/ConnectionHandlerExample.swift
+++ b/Sources/ConnectionHandlerExample/ConnectionHandlerExample.swift
@@ -22,7 +22,7 @@ import NIOHTTPServer
 import X509
 
 @main
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct ConnectionHandlerExample {
     static func main() async throws {
         try await serve()
diff --git a/Sources/NIOHTTPServer/Configuration/HTTP3/HTTP3+ConnectionSettings.swift b/Sources/NIOHTTPServer/Configuration/HTTP3/HTTP3+ConnectionSettings.swift
index 6f77248..58fb2e0 100644
--- a/Sources/NIOHTTPServer/Configuration/HTTP3/HTTP3+ConnectionSettings.swift
+++ b/Sources/NIOHTTPServer/Configuration/HTTP3/HTTP3+ConnectionSettings.swift
@@ -15,7 +15,7 @@
 #if HTTP3
 import HTTP3
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.HTTP3 {
     /// HTTP/3 connection settings sent to the peer during connection establishment.
     public struct ConnectionSettings: Sendable, Hashable {
@@ -53,7 +53,7 @@ extension NIOHTTPServerConfiguration.HTTP3 {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension HTTP3.HTTP3Settings {
     init(_ connectionConfiguration: NIOHTTPServerConfiguration.HTTP3.ConnectionSettings) {
         self.init(
diff --git a/Sources/NIOHTTPServer/Configuration/HTTP3/HTTP3+DatagramConfiguration.swift b/Sources/NIOHTTPServer/Configuration/HTTP3/HTTP3+DatagramConfiguration.swift
index b6765aa..a4f8484 100644
--- a/Sources/NIOHTTPServer/Configuration/HTTP3/HTTP3+DatagramConfiguration.swift
+++ b/Sources/NIOHTTPServer/Configuration/HTTP3/HTTP3+DatagramConfiguration.swift
@@ -13,7 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #if HTTP3 && UnstableHTTPDatagrams
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.HTTP3 {
     public struct DatagramConfiguration: Sendable, Hashable {
         /// The maximum datagram frame size in bytes.
diff --git a/Sources/NIOHTTPServer/Configuration/HTTP3/HTTP3+QUICConfiguration.swift b/Sources/NIOHTTPServer/Configuration/HTTP3/HTTP3+QUICConfiguration.swift
index ba4e904..545bb61 100644
--- a/Sources/NIOHTTPServer/Configuration/HTTP3/HTTP3+QUICConfiguration.swift
+++ b/Sources/NIOHTTPServer/Configuration/HTTP3/HTTP3+QUICConfiguration.swift
@@ -15,7 +15,7 @@
 #if HTTP3
 import NIOQUIC
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.HTTP3 {
     /// QUIC transport configuration for an HTTP/3 server.
     public struct QUICConfiguration: Sendable, Hashable {
@@ -206,7 +206,7 @@ extension NIOHTTPServerConfiguration.HTTP3 {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOQUIC.QUICConfiguration.QLogConfiguration {
     fileprivate init(_ configuration: NIOHTTPServerConfiguration.HTTP3.QUICConfiguration.QLogConfiguration) {
         self.init(
@@ -217,7 +217,7 @@ extension NIOQUIC.QUICConfiguration.QLogConfiguration {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOQUIC.KeyExchangeGroup {
     fileprivate init(_ configuration: NIOHTTPServerConfiguration.HTTP3.QUICConfiguration.KeyExchangeGroup) {
         switch configuration.backing {
@@ -236,7 +236,7 @@ extension NIOQUIC.KeyExchangeGroup {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOQUIC.AuthenticationConfiguration {
     init(_ tlsCredentials: NIOHTTPServerConfiguration.TransportSecurity.TLSCredentials) throws {
         switch tlsCredentials.backing {
@@ -261,7 +261,7 @@ extension NIOQUIC.AuthenticationConfiguration {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOQUIC.QUICConfiguration {
     /// Creates a `NIOQUIC.QUICConfiguration` from a `NIOHTTPServerConfiguration.HTTP3.QUICConfiguration` instance.
     init(
@@ -302,7 +302,7 @@ extension NIOQUIC.QUICConfiguration {
     #endif  // UnstableHTTPDatagrams
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOQUIC.Authenticator {
     /// Creates an `Authenticator` instance from X.509 TLS credentials.
     ///
diff --git a/Sources/NIOHTTPServer/Configuration/HTTP3/NIOHTTPServerConfiguration+HTTP3.swift b/Sources/NIOHTTPServer/Configuration/HTTP3/NIOHTTPServerConfiguration+HTTP3.swift
index c26ce18..2bbe556 100644
--- a/Sources/NIOHTTPServer/Configuration/HTTP3/NIOHTTPServerConfiguration+HTTP3.swift
+++ b/Sources/NIOHTTPServer/Configuration/HTTP3/NIOHTTPServerConfiguration+HTTP3.swift
@@ -16,7 +16,7 @@
 import NIOCore
 import NIOHTTP3
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration {
     /// Configuration for HTTP/3.
     public struct HTTP3: Sendable, Hashable {
@@ -105,7 +105,7 @@ extension NIOHTTPServerConfiguration {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTP3.HTTP3ServerConfiguration {
     init(_ configuration: NIOHTTPServerConfiguration.HTTP3) {
         self = .defaults
diff --git a/Sources/NIOHTTPServer/Configuration/NIOHTTPServerConfiguration+Validation.swift b/Sources/NIOHTTPServer/Configuration/NIOHTTPServerConfiguration+Validation.swift
index 6ae2780..a799aec 100644
--- a/Sources/NIOHTTPServer/Configuration/NIOHTTPServerConfiguration+Validation.swift
+++ b/Sources/NIOHTTPServer/Configuration/NIOHTTPServerConfiguration+Validation.swift
@@ -18,7 +18,7 @@ import NIOSSL
 import NIOQUIC
 #endif
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration {
     /// Validates the compatibility of the `supportedHTTPVersions` and `transportSecurity` configurations, and stores
     /// the TLS resources required to set up the server channels.
diff --git a/Sources/NIOHTTPServer/Configuration/NIOHTTPServerConfiguration.swift b/Sources/NIOHTTPServer/Configuration/NIOHTTPServerConfiguration.swift
index da1200b..9a3f60f 100644
--- a/Sources/NIOHTTPServer/Configuration/NIOHTTPServerConfiguration.swift
+++ b/Sources/NIOHTTPServer/Configuration/NIOHTTPServerConfiguration.swift
@@ -24,7 +24,7 @@ import NIOQUIC
 ///
 /// This structure contains all the necessary configuration options for setting up
 /// and running ``NIOHTTPServer``, including network binding and TLS settings.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 public struct NIOHTTPServerConfiguration: Sendable {
     /// Specifies where the server should bind and listen for incoming connections.
     ///
@@ -444,7 +444,7 @@ public struct NIOHTTPServerConfiguration: Sendable {
 ///
 /// Indicates whether certificate verification succeeded or failed, and provides associated metadata when verification
 /// is successful.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 public enum CertificateVerificationResult: Sendable, Hashable {
     /// Metadata resulting from successful certificate verification.
     public struct VerificationMetadata: Sendable, Hashable {
@@ -512,7 +512,7 @@ public struct CertificateVerificationMode: Sendable {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOSSL.CertificateVerification {
     /// Maps ``CertificateVerificationMode`` to the NIOSSL representation.
     init(_ verificationMode: CertificateVerificationMode) {
@@ -525,7 +525,7 @@ extension NIOSSL.CertificateVerification {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration {
     /// Represents an HTTP version.
     public struct HTTPVersion: Sendable, Hashable {
@@ -638,7 +638,7 @@ extension NIOHTTPServerConfiguration {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOAsyncSequenceProducerBackPressureStrategies.HighLowWatermark {
     init(_ backpressureStrategy: NIOHTTPServerConfiguration.BackPressureStrategy) {
         switch backpressureStrategy.backing {
@@ -648,7 +648,7 @@ extension NIOAsyncSequenceProducerBackPressureStrategies.HighLowWatermark {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension Set where Element == NIOHTTPServerConfiguration.HTTPVersion {
     /// The ALPN protocol identifiers to advertise during the TLS handshake, derived from the supported HTTP versions.
     ///
diff --git a/Sources/NIOHTTPServer/Configuration/SwiftConfiguration/HTTP2+SwiftConfiguration.swift b/Sources/NIOHTTPServer/Configuration/SwiftConfiguration/HTTP2+SwiftConfiguration.swift
index 2d630fd..d738424 100644
--- a/Sources/NIOHTTPServer/Configuration/SwiftConfiguration/HTTP2+SwiftConfiguration.swift
+++ b/Sources/NIOHTTPServer/Configuration/SwiftConfiguration/HTTP2+SwiftConfiguration.swift
@@ -15,7 +15,7 @@
 #if Configuration
 public import Configuration
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.HTTP2 {
     /// Initialize an HTTP/2 configuration from a config reader.
     ///
diff --git a/Sources/NIOHTTPServer/Configuration/SwiftConfiguration/HTTP3+SwiftConfiguration.swift b/Sources/NIOHTTPServer/Configuration/SwiftConfiguration/HTTP3+SwiftConfiguration.swift
index fa63b72..34f0537 100644
--- a/Sources/NIOHTTPServer/Configuration/SwiftConfiguration/HTTP3+SwiftConfiguration.swift
+++ b/Sources/NIOHTTPServer/Configuration/SwiftConfiguration/HTTP3+SwiftConfiguration.swift
@@ -15,7 +15,7 @@
 #if HTTP3 && Configuration
 public import Configuration
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.HTTP3 {
     /// Initialize an HTTP/3 configuration from a config reader.
     ///
@@ -53,7 +53,7 @@ extension NIOHTTPServerConfiguration.HTTP3 {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.HTTP3.QUICConfiguration {
     /// Initialize a QUIC transport configuration from a config reader.
     ///
@@ -126,7 +126,7 @@ extension NIOHTTPServerConfiguration.HTTP3.QUICConfiguration {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.HTTP3.QUICConfiguration.QLogConfiguration {
     /// Initialize an optional qlog configuration from a config reader.
     ///
@@ -166,7 +166,7 @@ private enum KeyExchangeGroupKind: String {
     case x25519MLKEM768
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.HTTP3.QUICConfiguration.KeyExchangeGroup {
     fileprivate init(_ kind: KeyExchangeGroupKind) {
         switch kind {
@@ -182,7 +182,7 @@ extension NIOHTTPServerConfiguration.HTTP3.QUICConfiguration.KeyExchangeGroup {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.HTTP3.ConnectionSettings {
     /// Initialize HTTP/3 connection settings from a config reader.
     ///
@@ -212,7 +212,7 @@ extension NIOHTTPServerConfiguration.HTTP3.ConnectionSettings {
 }
 
 #if UnstableHTTPDatagrams
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.HTTP3.DatagramConfiguration {
     /// Initialize HTTP/3 connection settings from a config reader.
     ///
diff --git a/Sources/NIOHTTPServer/Configuration/SwiftConfiguration/NIOHTTPServer+SwiftConfiguration.swift b/Sources/NIOHTTPServer/Configuration/SwiftConfiguration/NIOHTTPServer+SwiftConfiguration.swift
index e2c333c..83b6936 100644
--- a/Sources/NIOHTTPServer/Configuration/SwiftConfiguration/NIOHTTPServer+SwiftConfiguration.swift
+++ b/Sources/NIOHTTPServer/Configuration/SwiftConfiguration/NIOHTTPServer+SwiftConfiguration.swift
@@ -20,7 +20,7 @@ import NIOHTTP2
 import SwiftASN1
 public import X509
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration {
     /// Initialize the server configuration from a config reader.
     ///
@@ -124,7 +124,7 @@ extension NIOHTTPServerConfiguration {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.BindTarget {
     /// Initialize a bind target configuration from a config reader.
     ///
@@ -143,7 +143,7 @@ extension NIOHTTPServerConfiguration.BindTarget {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension Set where Element == NIOHTTPServerConfiguration.HTTPVersion {
     /// Initialize a supported HTTP versions configuration from a config reader.
     ///
@@ -189,7 +189,7 @@ extension Set where Element == NIOHTTPServerConfiguration.HTTPVersion {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.TransportSecurity {
     /// Initialize a transport security configuration from a config reader.
     ///
@@ -264,7 +264,7 @@ extension NIOHTTPServerConfiguration.TransportSecurity {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.TransportSecurity.TLSCredentials {
     /// Initialize TLS credentials (certificate chain and private key) from a config reader.
     ///
@@ -324,7 +324,7 @@ extension NIOHTTPServerConfiguration.TransportSecurity.TLSCredentials {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.TransportSecurity.MTLSTrustConfiguration {
     /// Initialize an mTLS trust configuration from a config reader.
     ///
@@ -398,7 +398,7 @@ extension NIOHTTPServerConfiguration.TransportSecurity.MTLSTrustConfiguration {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.BackPressureStrategy {
     /// Initialize the backpressure strategy configuration from a config reader.
     ///
@@ -425,7 +425,7 @@ extension NIOHTTPServerConfiguration.BackPressureStrategy {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension Set where Element == NIOHTTPServerConfiguration.HTTPVersion {
     fileprivate enum HTTPVersionKind: String {
         case http1_1
@@ -436,7 +436,7 @@ extension Set where Element == NIOHTTPServerConfiguration.HTTPVersion {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.TransportSecurity {
     fileprivate enum TransportSecurityMode: String {
         case plaintext
@@ -453,7 +453,7 @@ extension NIOHTTPServerConfiguration.TransportSecurity {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.TransportSecurity.MTLSTrustConfiguration {
     /// The supported sources for trust roots.
     fileprivate enum TrustRootsSource: String {
@@ -470,7 +470,7 @@ extension NIOHTTPServerConfiguration.TransportSecurity.MTLSTrustConfiguration {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension CertificateVerificationMode {
     fileprivate init(_ mode: NIOHTTPServerConfiguration.TransportSecurity.MTLSTrustConfiguration.VerificationMode) {
         switch mode {
@@ -482,7 +482,7 @@ extension CertificateVerificationMode {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.ConnectionTimeouts {
     /// Initialize connection timeouts configuration from a config reader.
     ///
@@ -503,7 +503,7 @@ extension NIOHTTPServerConfiguration.ConnectionTimeouts {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.GracefulShutdownConfiguration {
     /// Initialize a graceful shutdown configuration from a config reader.
     ///
diff --git a/Sources/NIOHTTPServer/Configuration/TransportSecurity+MTLSTrustConfiguration.swift b/Sources/NIOHTTPServer/Configuration/TransportSecurity+MTLSTrustConfiguration.swift
index e8905aa..f9db84d 100644
--- a/Sources/NIOHTTPServer/Configuration/TransportSecurity+MTLSTrustConfiguration.swift
+++ b/Sources/NIOHTTPServer/Configuration/TransportSecurity+MTLSTrustConfiguration.swift
@@ -16,7 +16,7 @@ import NIOCore
 import NIOSSL
 public import X509
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.TransportSecurity {
     /// Configures how the server verifies client certificates during mTLS.
     public struct MTLSTrustConfiguration: Sendable {
@@ -45,7 +45,7 @@ extension NIOHTTPServerConfiguration.TransportSecurity {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.TransportSecurity.MTLSTrustConfiguration {
     public struct TrustSource: Sendable {
         enum Backing {
diff --git a/Sources/NIOHTTPServer/Configuration/TransportSecurity+NIOSSL.swift b/Sources/NIOHTTPServer/Configuration/TransportSecurity+NIOSSL.swift
index 0f5f2cd..a04cae9 100644
--- a/Sources/NIOHTTPServer/Configuration/TransportSecurity+NIOSSL.swift
+++ b/Sources/NIOHTTPServer/Configuration/TransportSecurity+NIOSSL.swift
@@ -16,7 +16,7 @@ import NIOCertificateReloading
 import NIOSSL
 import X509
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOSSLContext {
     /// Creates a `NIOSSL.NIOSSLContext` from the server's transport security configuration.
     static func makeServerContext(
@@ -67,7 +67,7 @@ extension NIOSSLContext {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension TLSConfiguration {
     /// Creates a server `TLSConfiguration` from the provided X.509 credentials.
     fileprivate static func makeServerConfiguration(
@@ -89,7 +89,7 @@ extension TLSConfiguration {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension [NIOSSLCertificateSource] {
     fileprivate init(
         _ serialized: NIOHTTPServerConfiguration.TransportSecurity.X509Credentials.SerializedCredentials
@@ -110,7 +110,7 @@ extension [NIOSSLCertificateSource] {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOSSLPrivateKeySource {
     fileprivate init(
         _ serialized: NIOHTTPServerConfiguration.TransportSecurity.X509Credentials.SerializedCredentials
@@ -125,7 +125,7 @@ extension NIOSSLPrivateKeySource {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOSSLTrustRoots {
     fileprivate init(
         _ serialized: NIOHTTPServerConfiguration.TransportSecurity.MTLSTrustConfiguration.SerializedTrustRoots
@@ -146,7 +146,7 @@ extension NIOSSLTrustRoots {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOSSLSerializationFormats {
     fileprivate init(_ format: NIOHTTPServerConfiguration.TransportSecurity.Encoding) {
         switch format {
diff --git a/Sources/NIOHTTPServer/Configuration/TransportSecurity+TLSCredentials.swift b/Sources/NIOHTTPServer/Configuration/TransportSecurity+TLSCredentials.swift
index 31b3c7a..6343fa9 100644
--- a/Sources/NIOHTTPServer/Configuration/TransportSecurity+TLSCredentials.swift
+++ b/Sources/NIOHTTPServer/Configuration/TransportSecurity+TLSCredentials.swift
@@ -15,7 +15,7 @@
 public import NIOCertificateReloading
 public import X509
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.TransportSecurity {
     /// Represents the credentials the server uses to prove its identity during the TLS handshake.
     ///
diff --git a/Sources/NIOHTTPServer/Datagrams/ConnectUDPExample.swift b/Sources/NIOHTTPServer/Datagrams/ConnectUDPExample.swift
index 2393349..c288df7 100644
--- a/Sources/NIOHTTPServer/Datagrams/ConnectUDPExample.swift
+++ b/Sources/NIOHTTPServer/Datagrams/ConnectUDPExample.swift
@@ -20,7 +20,7 @@ import NIOCore
 import NIOHTTPTypes
 import NetworkTypes
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 func connectUDPExample(
     request: HTTPRequest,
     context: NIOHTTPServer.ConnectionContext,
@@ -124,7 +124,7 @@ final class RefBox<Value: ~Copyable> {
 }
 extension RefBox: Sendable where Value: Sendable & ~Copyable {}
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 enum ConnectUDPHelper {
     /// Validate that `request` corresponds to a valid CONNECT-UDP request.
     static func isValidConnectUDPRequest(_ request: HTTPRequest, version: NIOHTTPServer.HTTPVersion) -> Bool {
diff --git a/Sources/NIOHTTPServer/Datagrams/HTTP3ConnectionManager.swift b/Sources/NIOHTTPServer/Datagrams/HTTP3ConnectionManager.swift
index 9479b5b..43dd784 100644
--- a/Sources/NIOHTTPServer/Datagrams/HTTP3ConnectionManager.swift
+++ b/Sources/NIOHTTPServer/Datagrams/HTTP3ConnectionManager.swift
@@ -19,7 +19,7 @@ import NIOHTTP3
 import NIOQUICHelpers
 
 /// Routes inbound HTTP/3 datagrams to registered ``HTTP3DatagramStream`` instances.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 final class HTTP3ConnectionManager: ChannelInboundHandler {
     typealias InboundIn = HTTP3Datagram
 
diff --git a/Sources/NIOHTTPServer/Datagrams/HTTP3UnreliableDatagramStream.swift b/Sources/NIOHTTPServer/Datagrams/HTTP3UnreliableDatagramStream.swift
index 76ad03d..d95cdb6 100644
--- a/Sources/NIOHTTPServer/Datagrams/HTTP3UnreliableDatagramStream.swift
+++ b/Sources/NIOHTTPServer/Datagrams/HTTP3UnreliableDatagramStream.swift
@@ -18,7 +18,7 @@ import NIOCore
 import NIOHTTP3
 import NIOQUICHelpers
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct HTTP3UnreliableDatagramStream: Sendable {
     // The QUIC stream ID.
     let streamID: QUICStreamID
diff --git a/Sources/NIOHTTPServer/Datagrams/NIOHTTPServer+Datagrams.swift b/Sources/NIOHTTPServer/Datagrams/NIOHTTPServer+Datagrams.swift
index 40ba1be..2c572b7 100644
--- a/Sources/NIOHTTPServer/Datagrams/NIOHTTPServer+Datagrams.swift
+++ b/Sources/NIOHTTPServer/Datagrams/NIOHTTPServer+Datagrams.swift
@@ -20,7 +20,7 @@ import NIOCore
 import NIOHTTPTypes
 import Synchronization
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     /// A reader for the unreliable datagram stream.
     public struct DatagramReader: AsyncReader, ~Copyable {
diff --git a/Sources/NIOHTTPServer/HTTPKeepAliveHandler.swift b/Sources/NIOHTTPServer/HTTPKeepAliveHandler.swift
index e8dc868..6714b1e 100644
--- a/Sources/NIOHTTPServer/HTTPKeepAliveHandler.swift
+++ b/Sources/NIOHTTPServer/HTTPKeepAliveHandler.swift
@@ -36,7 +36,7 @@ import NIOHTTPTypes
 ///
 /// Informational (1xx) responses pass through unchanged and do not affect buffering
 /// state.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 final class HTTPKeepAliveHandler: ChannelDuplexHandler {
     typealias InboundIn = HTTPRequestPart
     typealias InboundOut = HTTPRequestPart
diff --git a/Sources/NIOHTTPServer/HTTPServerCapability+ConnectionCapabilities.swift b/Sources/NIOHTTPServer/HTTPServerCapability+ConnectionCapabilities.swift
index 63b71fb..e33bdfb 100644
--- a/Sources/NIOHTTPServer/HTTPServerCapability+ConnectionCapabilities.swift
+++ b/Sources/NIOHTTPServer/HTTPServerCapability+ConnectionCapabilities.swift
@@ -15,7 +15,7 @@
 public import HTTPAPIs
 public import X509
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension HTTPServerCapability {
     /// A request-context capability exposing connection-scoped peer and local addresses.
     ///
diff --git a/Sources/NIOHTTPServer/ListenerConfiguration.swift b/Sources/NIOHTTPServer/ListenerConfiguration.swift
index b9ad20c..31726b0 100644
--- a/Sources/NIOHTTPServer/ListenerConfiguration.swift
+++ b/Sources/NIOHTTPServer/ListenerConfiguration.swift
@@ -19,7 +19,7 @@ import NIOQUIC
 #endif
 
 /// The listeners to bind, derived from the server configuration.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 enum ListenerConfiguration: Sendable {
     struct SecureUpgrade: Sendable {
         let sslContext: NIOSSLContext
@@ -42,7 +42,7 @@ enum ListenerConfiguration: Sendable {
     #endif
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration {
     func makeListenerConfiguration() -> ListenerConfiguration {
         let secureUpgrade = self.sslContext.map {
diff --git a/Sources/NIOHTTPServer/NIOHTTPServer+AbortRequest.swift b/Sources/NIOHTTPServer/NIOHTTPServer+AbortRequest.swift
index d42fa08..bae2cdf 100644
--- a/Sources/NIOHTTPServer/NIOHTTPServer+AbortRequest.swift
+++ b/Sources/NIOHTTPServer/NIOHTTPServer+AbortRequest.swift
@@ -22,7 +22,7 @@ import HTTP3
 import NIOQUICHelpers
 #endif
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     /// Aborts the exchange carrying a request on the wire, after that request's handler threw `error`.
     ///
diff --git a/Sources/NIOHTTPServer/NIOHTTPServer+Connection.swift b/Sources/NIOHTTPServer/NIOHTTPServer+Connection.swift
index fd8cd3a..2ea09f8 100644
--- a/Sources/NIOHTTPServer/NIOHTTPServer+Connection.swift
+++ b/Sources/NIOHTTPServer/NIOHTTPServer+Connection.swift
@@ -21,7 +21,7 @@ import NIOHTTPTypes
 import NIOQUIC
 #endif
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     /// An active HTTP server connection.
     ///
diff --git a/Sources/NIOHTTPServer/NIOHTTPServer+ConnectionContext.swift b/Sources/NIOHTTPServer/NIOHTTPServer+ConnectionContext.swift
index c5ecf71..7b3dd41 100644
--- a/Sources/NIOHTTPServer/NIOHTTPServer+ConnectionContext.swift
+++ b/Sources/NIOHTTPServer/NIOHTTPServer+ConnectionContext.swift
@@ -16,7 +16,7 @@ import NIOCore
 import NIOSSL
 public import X509
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     /// The application-level HTTP version negotiated for a connection.
     @nonexhaustive
@@ -30,7 +30,7 @@ extension NIOHTTPServer {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     /// Connection-scoped state.
     ///
diff --git a/Sources/NIOHTTPServer/NIOHTTPServer+HTTP1_1.swift b/Sources/NIOHTTPServer/NIOHTTPServer+HTTP1_1.swift
index c0401f7..192c831 100644
--- a/Sources/NIOHTTPServer/NIOHTTPServer+HTTP1_1.swift
+++ b/Sources/NIOHTTPServer/NIOHTTPServer+HTTP1_1.swift
@@ -21,7 +21,7 @@ import NIOHTTPTypesHTTP1
 import NIOPosix
 import NIOSSL
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     /// Serves incoming plaintext HTTP/1.1 connections.
     ///
diff --git a/Sources/NIOHTTPServer/NIOHTTPServer+HTTP3.swift b/Sources/NIOHTTPServer/NIOHTTPServer+HTTP3.swift
index bd4aa93..f7a0e37 100644
--- a/Sources/NIOHTTPServer/NIOHTTPServer+HTTP3.swift
+++ b/Sources/NIOHTTPServer/NIOHTTPServer+HTTP3.swift
@@ -27,7 +27,7 @@ import NIOSSL
 import ServiceLifecycle
 import X509
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     /// An inbound HTTP/3 request stream.
     struct HTTP3Stream: Sendable {
@@ -545,7 +545,7 @@ extension NIOHTTPServer {
 }
 
 /// Identifies one of the datagram sockets bound for a bind target, and the group it belongs to.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct HTTP3ListenerSocket: Sendable {
     /// The index of this socket within its associated group (will be zero if there is no group).
     var index: Int
diff --git a/Sources/NIOHTTPServer/NIOHTTPServer+ListeningAddress.swift b/Sources/NIOHTTPServer/NIOHTTPServer+ListeningAddress.swift
index 3fe7943..d4b63b4 100644
--- a/Sources/NIOHTTPServer/NIOHTTPServer+ListeningAddress.swift
+++ b/Sources/NIOHTTPServer/NIOHTTPServer+ListeningAddress.swift
@@ -35,7 +35,7 @@ enum ListeningAddressError: CustomStringConvertible, Error {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     func addressesBound(_ addresses: [NIOCore.SocketAddress?]) {
         switch self.listeningAddressState.withLockedValue({ $0.addressesBound(addresses) }) {
@@ -63,7 +63,7 @@ extension NIOHTTPServer {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     enum State {
         case idle(EventLoopPromise<[SocketAddress]>)
@@ -131,7 +131,7 @@ extension NIOHTTPServer {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer.SocketAddress {
     init(_ address: NIOCore.SocketAddress?) throws(ListeningAddressError) {
         guard let address, let port = address.port else {
@@ -151,7 +151,7 @@ extension NIOHTTPServer.SocketAddress {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.BindTarget {
     init(_ address: NIOCore.SocketAddress?) throws(ListeningAddressError) {
         guard let address, let port = address.port else {
diff --git a/Sources/NIOHTTPServer/NIOHTTPServer+RequestContext.swift b/Sources/NIOHTTPServer/NIOHTTPServer+RequestContext.swift
index b2db98f..7d4f145 100644
--- a/Sources/NIOHTTPServer/NIOHTTPServer+RequestContext.swift
+++ b/Sources/NIOHTTPServer/NIOHTTPServer+RequestContext.swift
@@ -16,7 +16,7 @@ public import HTTPAPIs
 import NIOCore
 public import X509
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     /// The request context provided to handlers by ``NIOHTTPServer``.
     ///
@@ -42,7 +42,7 @@ extension NIOHTTPServer {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer.RequestContext: HTTPServerCapability.ConnectionInfo {
     /// The peer's address, when known.
     ///
@@ -60,7 +60,7 @@ extension NIOHTTPServer.RequestContext: HTTPServerCapability.ConnectionInfo {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer.RequestContext: HTTPServerCapability.PeerCertificate {
     /// The peer's mTLS-validated certificate chain, when available.
     ///
diff --git a/Sources/NIOHTTPServer/NIOHTTPServer+SecureUpgrade.swift b/Sources/NIOHTTPServer/NIOHTTPServer+SecureUpgrade.swift
index 8d78bf5..95fbca7 100644
--- a/Sources/NIOHTTPServer/NIOHTTPServer+SecureUpgrade.swift
+++ b/Sources/NIOHTTPServer/NIOHTTPServer+SecureUpgrade.swift
@@ -27,7 +27,7 @@ import NIOSSL
 import NIOTLS
 import X509
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     struct NegotiationResult {
         enum NegotiatedChannel {
@@ -370,7 +370,7 @@ extension NIOHTTPServer {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOAsyncChannel where Inbound == HTTPRequestPart, Outbound == HTTPResponsePart {
     /// - Parameter clientClosed: Yields when the client stops waiting for a response, at which point `body`
     ///   is cancelled. Paired with the continuation held by this stream's `ClientClosedMonitor`.
@@ -433,7 +433,7 @@ extension NIOAsyncChannel where Inbound == HTTPRequestPart, Outbound == HTTPResp
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     func makeSSLServerHandler(
         _ sslContext: NIOSSLContext,
diff --git a/Sources/NIOHTTPServer/NIOHTTPServer.swift b/Sources/NIOHTTPServer/NIOHTTPServer.swift
index 1f43ffe..40eb530 100644
--- a/Sources/NIOHTTPServer/NIOHTTPServer.swift
+++ b/Sources/NIOHTTPServer/NIOHTTPServer.swift
@@ -68,7 +68,7 @@ import NIOQUIC
 ///
 /// A request handler reports failure by throwing, which aborts that request's exchange on the wire rather than
 /// propagating an error to the caller. See ``serve(handler:)`` and ``HTTPServerHTTP2StreamResetErrorConvertible``.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 public struct NIOHTTPServer: HTTPServer {
     let logger: Logger
     let configuration: NIOHTTPServerConfiguration
@@ -440,7 +440,7 @@ public struct NIOHTTPServer: HTTPServer {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension ChannelPipeline.SynchronousOperations {
     /// Adds timeout handlers (idle, read header, read body) to the channel pipeline.
     ///
@@ -493,7 +493,7 @@ extension ChannelPipeline.SynchronousOperations {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTP2Handler.Configuration {
     init(httpServerHTTP2Configuration http2Config: NIOHTTPServerConfiguration.HTTP2) {
         let clampedTargetWindowSize = Self.clampTargetWindowSize(http2Config.targetWindowSize)
@@ -564,13 +564,13 @@ extension NIOAsyncChannelInboundStream<HTTPRequestPart>.AsyncIterator {
 /// ``ClientClosedMonitor`` while its pipeline is built, so this is what carries the stream out to the code
 /// that races against it. HTTP/3 streams carry theirs in ``NIOHTTPServer/HTTP3Stream`` instead, which
 /// already bundles per-stream state.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct HTTPRequestChannelAndCancellationSignal: Sendable {
     var channel: NIOAsyncChannel<HTTPRequestPart, HTTPResponsePart>
     var clientClosed: AsyncStream<Void>
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension ServerBootstrap {
     /// Makes a `ServerBootstrap` alongside the `ServerQuiescingHelper` used to later shut that listener down gracefully.
     ///
@@ -601,7 +601,7 @@ extension ServerBootstrap {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     /// Awaits the next address from `iterator`.
     func nextBoundAddress(
diff --git a/Sources/NIOHTTPServer/NIOHTTPServerClosureConnectionHandler.swift b/Sources/NIOHTTPServer/NIOHTTPServerClosureConnectionHandler.swift
index a252cbb..6fa9351 100644
--- a/Sources/NIOHTTPServer/NIOHTTPServerClosureConnectionHandler.swift
+++ b/Sources/NIOHTTPServer/NIOHTTPServerClosureConnectionHandler.swift
@@ -16,7 +16,7 @@
 ///
 /// Used internally by ``NIOHTTPServer/NIOHTTPServer/serve(connectionHandler:)-((NIOHTTPServer.Connection,NIOHTTPServer.ConnectionContext)->Void)``
 /// to bridge a closure to the protocol-based connection-handler API.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct NIOHTTPServerClosureConnectionHandler: NIOHTTPServerConnectionHandler {
     let body:
         @Sendable (
diff --git a/Sources/NIOHTTPServer/NIOHTTPServerConnectionHandler.swift b/Sources/NIOHTTPServer/NIOHTTPServerConnectionHandler.swift
index 2a0573a..8067945 100644
--- a/Sources/NIOHTTPServer/NIOHTTPServerConnectionHandler.swift
+++ b/Sources/NIOHTTPServer/NIOHTTPServerConnectionHandler.swift
@@ -27,7 +27,7 @@
 /// ``NIOHTTPServer/serve(connectionHandler:)-((Connection,ConnectionContext)->Void)`` (the closure-based form). If only
 /// request-level handling is needed, prefer ``NIOHTTPServer/NIOHTTPServer/serve(handler:)``, which uses a built-in
 /// default connection handler (see ``NIOHTTPServer/NIOHTTPServerDefaultConnectionHandler``)
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 public protocol NIOHTTPServerConnectionHandler: Sendable {
     /// Handle a single connection.
     ///
diff --git a/Sources/NIOHTTPServer/NIOHTTPServerDefaultConnectionHandler.swift b/Sources/NIOHTTPServer/NIOHTTPServerDefaultConnectionHandler.swift
index c452ab6..50dadc9 100644
--- a/Sources/NIOHTTPServer/NIOHTTPServerDefaultConnectionHandler.swift
+++ b/Sources/NIOHTTPServer/NIOHTTPServerDefaultConnectionHandler.swift
@@ -20,7 +20,7 @@ public import HTTPAPIs
 /// This is the default connection handler used by ``NIOHTTPServer/serve(handler:)``.
 /// User code may also instantiate it directly when it wants to pass a request
 /// handler through a connection-handler API without doing per-connection work.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 public struct NIOHTTPServerDefaultConnectionHandler<Handler: HTTPServerRequestHandler>:
     NIOHTTPServerConnectionHandler
 where
diff --git a/Sources/NIOHTTPServer/NIOHTTPServerReader.swift b/Sources/NIOHTTPServer/NIOHTTPServerReader.swift
index f0be3b5..7fc73bf 100644
--- a/Sources/NIOHTTPServer/NIOHTTPServerReader.swift
+++ b/Sources/NIOHTTPServer/NIOHTTPServerReader.swift
@@ -17,7 +17,7 @@ import NIOCore
 import NIOHTTPTypes
 import Synchronization
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     public struct Reader: AsyncReader, ~Copyable {
         final class ReaderState: Sendable {
@@ -137,7 +137,7 @@ extension NIOHTTPServer {
 extension NIOHTTPServer.Reader: Sendable {}
 
 #if HTTP3 && UnstableHTTPDatagrams
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer.Reader {
     /// Returns the unreliable datagram reader for this stream, if both the server and the client have advertised
     /// support for receiving datagrams.
diff --git a/Sources/NIOHTTPServer/NIOHTTPServerResponseSender.swift b/Sources/NIOHTTPServer/NIOHTTPServerResponseSender.swift
index 543fd11..53050e7 100644
--- a/Sources/NIOHTTPServer/NIOHTTPServerResponseSender.swift
+++ b/Sources/NIOHTTPServer/NIOHTTPServerResponseSender.swift
@@ -16,7 +16,7 @@ import NIOCore
 import NIOHTTPTypes
 import Synchronization
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     public struct ResponseSender: HTTPResponseSender, ~Copyable {
         let writer: NIOAsyncChannelOutboundWriter<HTTPResponsePart>
@@ -69,7 +69,7 @@ extension NIOHTTPServer {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer.ResponseSender {
     final class WriterState: Sendable {
         struct Wrapped: ~Copyable {
@@ -163,6 +163,7 @@ extension NIOHTTPServer.ResponseSender: Sendable {}
 @available(*, unavailable)
 extension NIOHTTPServer.ResponseSender.Writer: Sendable {}
 
+@available(anyAppleOS 27.0, *)
 extension ByteBuffer {
     /// Drains `buffer` into a newly allocated `ByteBuffer`.
     init<Buffer: RangeReplaceableContainer<UInt8> & ~Copyable>(
diff --git a/Sources/NIOHTTPServer/QUICDatagramSocketGroup.swift b/Sources/NIOHTTPServer/QUICDatagramSocketGroup.swift
index 3f7c300..d943a9d 100644
--- a/Sources/NIOHTTPServer/QUICDatagramSocketGroup.swift
+++ b/Sources/NIOHTTPServer/QUICDatagramSocketGroup.swift
@@ -18,7 +18,7 @@ public import NIOCore
 public import NIOQUIC
 
 /// Used to bootstrap multiple datagram sockets sharing a single port for multithreaded QUIC.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 @_spi(QUICDatagramSockets)
 public protocol QUICDatagramSocketGroup: Sendable {
     /// How many sockets to bind for this bind target.
@@ -47,7 +47,7 @@ public protocol QUICDatagramSocketGroup: Sendable {
     func makeConnectionIDGenerator(socketIndex: Int) -> any QUICConnectionID.Generator
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 @_spi(QUICDatagramSockets)
 extension QUICDatagramSocketGroup {
     /// Default implementation: returns the default, random connection ID generator.
@@ -57,7 +57,7 @@ extension QUICDatagramSocketGroup {
 }
 
 /// Provides a socket group used to bootstrap a bind target, or `nil` to fall back to single socket behavior.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 @_spi(QUICDatagramSockets)
 public struct QUICDatagramSocketGroupFactory: Sendable, Hashable {
     /// Because this type is just a wrapper around a closure, we need something to use for `Hashable` conformance.
diff --git a/Sources/NIOHTTPServer/SocketAddress.swift b/Sources/NIOHTTPServer/SocketAddress.swift
index 583ef79..abcb85b 100644
--- a/Sources/NIOHTTPServer/SocketAddress.swift
+++ b/Sources/NIOHTTPServer/SocketAddress.swift
@@ -14,7 +14,7 @@
 
 import NIOCore
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     /// Represents an IPv4 address.
     public struct IPv4: Hashable, Sendable {
@@ -113,7 +113,7 @@ extension NIOHTTPServer {
 }
 
 extension NIOCore.SocketAddress {
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     init(bindTarget: NIOHTTPServerConfiguration.BindTarget) throws {
         switch bindTarget.backing {
         case .hostAndPort(let host, let port):
diff --git a/Sources/RequestHandlerExample/RequestHandlerExample.swift b/Sources/RequestHandlerExample/RequestHandlerExample.swift
index 3a62c35..9b2fba9 100644
--- a/Sources/RequestHandlerExample/RequestHandlerExample.swift
+++ b/Sources/RequestHandlerExample/RequestHandlerExample.swift
@@ -22,7 +22,7 @@ import NIOHTTPServer
 import X509
 
 @main
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct RequestHandlerExample {
     static func main() async throws {
         try await serve()
diff --git a/Sources/StreamResetExample/StreamResetExample.swift b/Sources/StreamResetExample/StreamResetExample.swift
index 5fca65f..6d4b3af 100644
--- a/Sources/StreamResetExample/StreamResetExample.swift
+++ b/Sources/StreamResetExample/StreamResetExample.swift
@@ -54,7 +54,7 @@ extension TunnelFailure: HTTPServerHTTP3StreamResetErrorConvertible {
 struct UnexpectedFailure: Error {}
 
 @main
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct StreamResetExample {
     static func main() async throws {
         try await serve()
@@ -95,7 +95,7 @@ struct StreamResetExample {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.TransportSecurity.TLSCredentials {
     /// A throwaway self-signed certificate, so the example needs no files on disk.
     fileprivate static func selfSigned() throws -> Self {
diff --git a/Tests/NIOHTTPServerTests/ClientClosedTests.swift b/Tests/NIOHTTPServerTests/ClientClosedTests.swift
index fcf857c..4156ea3 100644
--- a/Tests/NIOHTTPServerTests/ClientClosedTests.swift
+++ b/Tests/NIOHTTPServerTests/ClientClosedTests.swift
@@ -38,7 +38,7 @@ struct ClientClosedTests {
     /// never will.
     static let detectionWindow = TimeAmount.seconds(2)
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "Client disconnect cancels a busy handler",
         arguments: NIOHTTPServer.HTTPVersion.allCases
@@ -131,7 +131,7 @@ struct ClientClosedTests {
 
     /// HTTP/2: a client cancelling a single stream must cancel that request's handler, while leaving
     /// the connection and any other requests on it alive.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("HTTP/2 stream reset by the client cancels that request's handler")
     func http2StreamResetCancelsBusyHandler() async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
@@ -173,7 +173,7 @@ struct ClientClosedTests {
     }
 
     #if HTTP3
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("HTTP/3 STOP_SENDING alone does not cancel the handler")
     func http3StopSendingAloneDoesNotCancel() async throws {
         let sawCancellation = try await Self.runHTTP3Handler(clientSends: [.stopSending], completeRequest: false)
@@ -185,7 +185,7 @@ struct ClientClosedTests {
 
     /// `STOP_SENDING` *after* the request end does cancel: with the client's FIN already received, the
     /// exchange is finished in both directions, so the QUIC layer closes the stream.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("HTTP/3 STOP_SENDING after the request end cancels the handler")
     func http3StopSendingAfterRequestEndCancels() async throws {
         let sawCancellation = try await Self.runHTTP3Handler(clientSends: [.stopSending], completeRequest: true)
@@ -198,7 +198,7 @@ struct ClientClosedTests {
         )
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("HTTP/3 RESET_STREAM alone does not cancel the handler")
     func http3ResetStreamAloneDoesNotCancel() async throws {
         let sawCancellation = try await Self.runHTTP3Handler(clientSends: [.resetStream], completeRequest: false)
@@ -208,7 +208,7 @@ struct ClientClosedTests {
         )
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("HTTP/3 RESET_STREAM followed by STOP_SENDING cancels the handler")
     func http3BothFramesCancel() async throws {
         let sawCancellation = try await Self.runHTTP3Handler(
@@ -243,7 +243,7 @@ struct ClientClosedTests {
     /// - Parameter completeRequest: whether the client finishes its request body. This matters: once the
     ///   request is fully received QUIC may ignore a `RESET_STREAM` (RFC 9000 § 3.2), so leaving it
     ///   incomplete is the only way the server can observe that frame.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     private static func runHTTP3Handler(
         clientSends frames: [H3CancelFrame],
         completeRequest: Bool
@@ -327,7 +327,7 @@ struct ClientClosedTests {
     /// Cancellation is not scoped to the client going away: a close the *server* decided on cancels the
     /// handler too. For example, a timeout closing the connection has already concluded that nobody is getting a
     /// response.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("A timeout closing the connection cancels the handler")
     func serverInitiatedCloseCancelsBusyHandler() async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
diff --git a/Tests/NIOHTTPServerTests/ConnectionBackpressureConfigurationTests.swift b/Tests/NIOHTTPServerTests/ConnectionBackpressureConfigurationTests.swift
index 3904424..70935d0 100644
--- a/Tests/NIOHTTPServerTests/ConnectionBackpressureConfigurationTests.swift
+++ b/Tests/NIOHTTPServerTests/ConnectionBackpressureConfigurationTests.swift
@@ -18,7 +18,7 @@ import Testing
 
 @Suite("Connection Backpressure Configuration")
 struct ConnectionBackpressureConfigurationTests {
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("maxConnections nil is the default")
     func maxConnectionsNilIsDefault() throws {
         let config = try NIOHTTPServerConfiguration(
@@ -29,7 +29,7 @@ struct ConnectionBackpressureConfigurationTests {
         #expect(config.maxConnections == nil)
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("ConnectionTimeouts defaults has expected values")
     func connectionTimeoutsDefaults() {
         let timeouts = NIOHTTPServerConfiguration.ConnectionTimeouts.defaults
@@ -38,7 +38,7 @@ struct ConnectionBackpressureConfigurationTests {
         #expect(timeouts.readBody == .seconds(60))
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("Valid maxConnections is accepted")
     func validMaxConnectionsAccepted() throws {
         var config = try NIOHTTPServerConfiguration(
@@ -50,7 +50,7 @@ struct ConnectionBackpressureConfigurationTests {
         #expect(config.maxConnections == 100)
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("Custom ConnectionTimeouts are preserved")
     func customConnectionTimeouts() throws {
         var config = try NIOHTTPServerConfiguration(
@@ -70,7 +70,7 @@ import Configuration
 
 @Suite("Connection Backpressure SwiftConfiguration")
 struct ConnectionBackpressureSwiftConfigurationTests {
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("SwiftConfiguration parses maxConnections")
     func parsesMaxConnections() throws {
         let provider = InMemoryProvider(values: [
@@ -86,7 +86,7 @@ struct ConnectionBackpressureSwiftConfigurationTests {
         #expect(serverConfig.maxConnections == 500)
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("SwiftConfiguration parses connectionTimeouts")
     func parsesConnectionTimeouts() throws {
         let provider = InMemoryProvider(values: [
@@ -106,7 +106,7 @@ struct ConnectionBackpressureSwiftConfigurationTests {
         #expect(serverConfig.connectionTimeouts.readBody == .seconds(45))
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("SwiftConfiguration uses defaults for absent fields")
     func usesDefaultsForAbsentFields() throws {
         let provider = InMemoryProvider(values: [
diff --git a/Tests/NIOHTTPServerTests/ConnectionBackpressureEndToEndTests.swift b/Tests/NIOHTTPServerTests/ConnectionBackpressureEndToEndTests.swift
index 41d85d4..f83a833 100644
--- a/Tests/NIOHTTPServerTests/ConnectionBackpressureEndToEndTests.swift
+++ b/Tests/NIOHTTPServerTests/ConnectionBackpressureEndToEndTests.swift
@@ -26,7 +26,7 @@ struct ConnectionBackpressureEndToEndTests {
     let serverLogger = Logger(label: "ConnectionBackpressureE2ETests.server")
     let clientLogger = Logger(label: "ConnectionBackpressureE2ETests.client")
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "Requests succeed under connection limit",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1, .http2]
@@ -80,7 +80,7 @@ struct ConnectionBackpressureEndToEndTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "More connections than maxConnections all eventually complete",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1, .http2]
@@ -135,7 +135,7 @@ struct ConnectionBackpressureEndToEndTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "No connection limit by default",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1, .http2]
diff --git a/Tests/NIOHTTPServerTests/ConnectionLifecycleTests.swift b/Tests/NIOHTTPServerTests/ConnectionLifecycleTests.swift
index ae17cd7..a671754 100644
--- a/Tests/NIOHTTPServerTests/ConnectionLifecycleTests.swift
+++ b/Tests/NIOHTTPServerTests/ConnectionLifecycleTests.swift
@@ -24,7 +24,7 @@ import Testing
 /// State observed by the connection handlers used in this test suite. The state lives
 /// in a class so it survives `consuming` calls to `handleConnection` and can be
 /// inspected from the test body.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 final class ConnectionLifecycleTestState: Sendable {
     let connectionInvocations = NIOLockedValueBox(0)
     let requestInvocations = NIOLockedValueBox(0)
@@ -35,7 +35,7 @@ final class ConnectionLifecycleTestState: Sendable {
 
 /// A connection handler that counts invocations and runs a single request handler
 /// for every request on the connection.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct CountingConnectionHandler<Handler: HTTPServerRequestHandler>: NIOHTTPServerConnectionHandler
 where
     Handler.RequestContext == NIOHTTPServer.RequestContext,
@@ -66,7 +66,7 @@ where
 }
 
 /// A request handler that increments two counters before delegating to the wrapped handler.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct ConnectionScopedRequestHandler<Wrapped: HTTPServerRequestHandler>: HTTPServerRequestHandler
 where
     Wrapped.RequestContext == NIOHTTPServer.RequestContext,
@@ -107,7 +107,7 @@ struct ConnectionLifecycleTests {
     /// drains the request body, which is required for the per-channel loop
     /// to recover the iterator and keep the HTTP/1.1 connection alive across
     /// requests.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     static func echoHandler() -> HTTPServerClosureRequestHandler<
         NIOHTTPServer.RequestContext,
         NIOHTTPServer.Reader,
@@ -120,7 +120,7 @@ struct ConnectionLifecycleTests {
 
     /// Connecting twice results in two `handleConnection` invocations, each with non-nil `remoteAddress` and
     /// `localAddress`.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "Per-connection invocation count",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1, .http2]
@@ -161,7 +161,7 @@ struct ConnectionLifecycleTests {
 
     /// HTTP/1.1 keep-alive: two requests on the same connection result in a single `handleConnection` invocation that
     /// runs the request handler twice.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "HTTP/1.1 keep-alive: single connection-handler invocation, multiple requests",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1]
@@ -203,7 +203,7 @@ struct ConnectionLifecycleTests {
     /// HTTP/2: three concurrent streams on one connection result in one `handleConnection` call and three
     /// request-handler calls. A user counter held by the connection handler observes three after `handleRequests`
     /// returns.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("HTTP/2: single connection-handler invocation, concurrent streams")
     func testHTTP2SingleInvocationConcurrentStreams() async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
@@ -276,7 +276,7 @@ struct ConnectionLifecycleTests {
     /// A throwing connection handler is logged at debug level by the server but
     /// doesn't bring it down: a subsequent connection on the same server is
     /// served normally.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "Throwing connection handler doesn't bring down the server",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1, .http2]
@@ -332,7 +332,7 @@ struct ConnectionLifecycleTests {
 
     /// A connection handler that returns without calling `handleRequests` effectively drops the connection: the channel
     /// closes immediately and the client sees EOF without any response.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "Connection handler returning without handleRequests drops the connection",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1, .http2]
@@ -373,7 +373,7 @@ struct ConnectionLifecycleTests {
     }
 
     /// `ConnectionContext.httpVersion` reflects the protocol negotiated for the connection.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("ConnectionContext.httpVersion is correct", arguments: NIOHTTPServer.HTTPVersion.allCases)
     func testHTTPVersion(httpVersion: NIOHTTPServer.HTTPVersion) async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
@@ -409,7 +409,7 @@ struct ConnectionLifecycleTests {
     /// Multiple HTTP/1.1 keep-alive connections in parallel each receive their own `handleConnection` invocation and
     /// connection-scoped state isn't shared between them. Each connection's per-request counter only reflects its own
     /// requests.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "State isolation across keep-alive HTTP/1.1 connections",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1]
@@ -462,7 +462,7 @@ struct ConnectionLifecycleTests {
     /// Smoke test for the closure-overload of
     /// ``NIOHTTPServer/Connection/handleRequests(handler:)-((@Sendable)``: a single request is served end-to-end
     /// without constructing an explicit ``HTTPServerClosureRequestHandler``.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("connection.handleRequests closure overload", .timeLimit(.minutes(1)))
     func testHandleRequestsClosureOverload() async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
@@ -495,7 +495,7 @@ struct ConnectionLifecycleTests {
 
 /// Connection handler that throws on the first invocation and runs normally thereafter, so the test can verify a thrown
 /// error doesn't bring down the server.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct ThrowingFirstConnectionHandler: NIOHTTPServerConnectionHandler {
     let connectionInvocations: NIOLockedValueBox<Int>
 
@@ -518,7 +518,7 @@ struct ThrowingFirstConnectionHandler: NIOHTTPServerConnectionHandler {
 
 /// Connection handler that records the invocation count and returns without
 /// calling `handleRequests`, dropping the connection.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct NoOpConnectionHandler: NIOHTTPServerConnectionHandler {
     let connectionInvocations: NIOLockedValueBox<Int>
 
@@ -534,7 +534,7 @@ struct NoOpConnectionHandler: NIOHTTPServerConnectionHandler {
 
 /// Connection handler that records the negotiated HTTP version on its first
 /// invocation and forwards every request to a wrapped handler.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct HTTPVersionRecordingConnectionHandler<Wrapped: HTTPServerRequestHandler>:
     NIOHTTPServerConnectionHandler
 where
@@ -558,7 +558,7 @@ where
 
 /// Connection handler that counts requests on its own connection and appends
 /// the final count to a shared array when the connection ends.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct PerConnectionCounterHandler<Wrapped: HTTPServerRequestHandler>: NIOHTTPServerConnectionHandler
 where
     Wrapped.RequestContext == NIOHTTPServer.RequestContext,
@@ -586,7 +586,7 @@ where
 
 /// Connection handler that uses the closure-overload of
 /// ``NIOHTTPServer/Connection/handleRequests(handler:)-((@Sendable)``.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct ClosureRequestHandlerConnectionHandler: NIOHTTPServerConnectionHandler {
     func handleConnection(
         connection: consuming sending NIOHTTPServer.Connection,
diff --git a/Tests/NIOHTTPServerTests/HTTP3ConfigurationTests.swift b/Tests/NIOHTTPServerTests/HTTP3ConfigurationTests.swift
index 65a3a28..cd87aa4 100644
--- a/Tests/NIOHTTPServerTests/HTTP3ConfigurationTests.swift
+++ b/Tests/NIOHTTPServerTests/HTTP3ConfigurationTests.swift
@@ -21,7 +21,7 @@ import Testing
 @Suite
 struct HTTP3ConfigurationTests {
     @Test("HTTP/3 default configuration uses the defaults of the sub-components")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func http3DefaultConfiguration() {
         let config = NIOHTTPServerConfiguration.HTTP3.defaults
         #expect(config.quicConfiguration == .defaults)
@@ -29,7 +29,7 @@ struct HTTP3ConfigurationTests {
     }
 
     @Test("HTTP/3 configuration with custom values")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func http3ConfigurationCustomValues() {
         var connectionSettings = NIOHTTPServerConfiguration.HTTP3.ConnectionSettings.defaults
         connectionSettings.qpackMaximumTableCapacity = 4096
@@ -57,7 +57,7 @@ struct HTTP3ConfigurationTests {
     @Suite
     struct AuthenticationConfigurationTests {
         @Test("In-memory TLS credentials are rejected")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func inMemoryCredentialsRejected() throws {
             let chain = try TestCA.makeSelfSignedChain()
             #expect(throws: NIOHTTPServerConfigurationError.onlyPEMFileX509CredentialsCurrentlySupportedOverHTTP3) {
@@ -68,7 +68,7 @@ struct HTTP3ConfigurationTests {
         }
 
         @Test("PEM-file TLS credentials are accepted")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func pemFileCredentialsAccepted() {
             #expect(throws: Never.self) {
                 _ = try NIOQUIC.AuthenticationConfiguration(
diff --git a/Tests/NIOHTTPServerTests/HTTP3DatagramTests.swift b/Tests/NIOHTTPServerTests/HTTP3DatagramTests.swift
index a7ac895..209c905 100644
--- a/Tests/NIOHTTPServerTests/HTTP3DatagramTests.swift
+++ b/Tests/NIOHTTPServerTests/HTTP3DatagramTests.swift
@@ -31,7 +31,7 @@ struct HTTP3DatagramTests {
     static let clientLogger = Logger(label: "HTTP3DatagramTests.client")
 
     @Test("Datagrams are routed to the request stream they belong to")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func datagramsAreRoutedByStreamID() async throws {
         let channel = EmbeddedChannel()
         let datagramsNegotiatedPromise = channel.eventLoop.makePromise(of: Void.self)
@@ -62,7 +62,7 @@ struct HTTP3DatagramTests {
     }
 
     @Test("Datagrams delivered after deregistering are dropped")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func datagramsAfterDeregisteringAreDropped() async throws {
         let channel = EmbeddedChannel()
         let datagramsNegotiatedPromise = channel.eventLoop.makePromise(of: Void.self)
@@ -86,7 +86,7 @@ struct HTTP3DatagramTests {
     }
 
     @Test("Closing the connection ends every registered datagram stream")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func closingTheConnectionEndsEveryDatagramStream() async throws {
         let channel = EmbeddedChannel()
         let datagramsNegotiatedPromise = channel.eventLoop.makePromise(of: Void.self)
@@ -114,7 +114,7 @@ struct HTTP3DatagramTests {
     }
 
     @Test("The oldest datagram is dropped once the buffer is full")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func oldestDatagramIsDroppedOnceTheBufferIsFull() async throws {
         let channel = EmbeddedChannel()
         let stream = HTTP3UnreliableDatagramStream(streamID: 0, connectionChannel: channel, maxBufferedDatagrams: 2)
@@ -130,7 +130,7 @@ struct HTTP3DatagramTests {
     }
 
     @Test("Each write is sent as one datagram containing the stream's ID")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func eachWriteIsSentAsOneDatagram() async throws {
         let channel = EmbeddedChannel()
 
@@ -169,7 +169,7 @@ struct HTTP3DatagramTests {
     }
 
     @Test("Finishing flushes any remaining bytes as a final datagram")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func finishingWritesRemainingBytes() async throws {
         let channel = EmbeddedChannel()
         let writer = NIOHTTPServer.DatagramWriter(
@@ -185,7 +185,7 @@ struct HTTP3DatagramTests {
     }
 
     @Test("Finishing with an empty buffer writes no datagram")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func finishingWithAnEmptyBufferWritesNoDatagram() async throws {
         let channel = EmbeddedChannel()
         let writer = NIOHTTPServer.DatagramWriter(
@@ -199,7 +199,7 @@ struct HTTP3DatagramTests {
     }
 
     @Test("Reading and writing datagrams are independent of each other")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func readingAndWritingAreIndependent() async throws {
         let channel = EmbeddedChannel()
         let stream = HTTP3UnreliableDatagramStream(streamID: 4, connectionChannel: channel, maxBufferedDatagrams: 16)
@@ -218,7 +218,7 @@ struct HTTP3DatagramTests {
     }
 
     @Test("Read and write datagrams")
-    @available(anyAppleOS 26.2, *)
+    @available(anyAppleOS 27.0, *)
     func readAndWriteDatagrams() async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
             for: .http3,
@@ -281,7 +281,7 @@ struct HTTP3DatagramTests {
     }
 
     @Test("Writing a datagram larger than the max_datagram_frame_size fails")
-    @available(anyAppleOS 26.2, *)
+    @available(anyAppleOS 27.0, *)
     func writingDatagramLargerThanMaxFrameSizeFails() async throws {
         let clientMaxDatagramFrameSize = 150
 
@@ -363,7 +363,7 @@ struct HTTP3DatagramTests {
     }
 
     @Test("Datagram reader and writer not vended when client does not support datagrams")
-    @available(anyAppleOS 26.2, *)
+    @available(anyAppleOS 27.0, *)
     func datagramReaderAndWriterNotVendedWhenNotSupportedByClient() async throws {
         var (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
             for: .http3,
diff --git a/Tests/NIOHTTPServerTests/HTTPKeepAliveHandlerTests.swift b/Tests/NIOHTTPServerTests/HTTPKeepAliveHandlerTests.swift
index f5c40e0..686f27a 100644
--- a/Tests/NIOHTTPServerTests/HTTPKeepAliveHandlerTests.swift
+++ b/Tests/NIOHTTPServerTests/HTTPKeepAliveHandlerTests.swift
@@ -31,7 +31,7 @@ struct HTTPKeepAliveHandlerTests {
     /// Verifies the happy case: when a client pipelines multiple HTTP/1.1 requests
     /// on a single connection, all responses are returned in order and the connection
     /// stays alive (no `Connection: close`).
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "Pipelined requests on a single connection all succeed",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1]
@@ -94,7 +94,7 @@ struct HTTPKeepAliveHandlerTests {
     /// Verifies that when the handler writes a short response (head + end, no body)
     /// before the request `.end` has arrived, the response head includes a
     /// `Connection: close` header and the server closes the connection.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "Server sends head+end (no body) before request .end — Connection: close in header",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1]
@@ -165,7 +165,7 @@ struct HTTPKeepAliveHandlerTests {
     /// the request `.end` has arrived; the client must receive that informational
     /// response immediately (without waiting for request `.end`), and the connection
     /// must remain alive after the final response.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "Informational (1xx) responses pass through without buffering or closing",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1]
@@ -272,7 +272,7 @@ struct HTTPKeepAliveHandlerTests {
     /// everything until request `.end` arrives. Because the head is flushed before
     /// request `.end` arrives, the response carries `Connection: close` and the
     /// server closes the connection after writing response `.end`.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "Bidirectional streaming works — head is flushed (with Connection: close) when a body part is written",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1]
@@ -351,7 +351,7 @@ struct HTTPKeepAliveHandlerTests {
     /// server reads the body chunk, the read cycle ends with the head still
     /// buffered and request `.end` still missing — the keep-alive handler must add
     /// `Connection: close`.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "Read cycle ends without request .end while head is buffered — Connection: close added",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1]
@@ -446,7 +446,7 @@ struct HTTPKeepAliveHandlerTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test func channelClosesOnConnectionError() async throws {
         let channel = EmbeddedChannel()
         try await channel.connect(to: try .init(ipAddress: "127.0.0.1", port: 0)).get()
diff --git a/Tests/NIOHTTPServerTests/HTTPServerTests.swift b/Tests/NIOHTTPServerTests/HTTPServerTests.swift
index 688d585..15b1142 100644
--- a/Tests/NIOHTTPServerTests/HTTPServerTests.swift
+++ b/Tests/NIOHTTPServerTests/HTTPServerTests.swift
@@ -20,7 +20,7 @@ import Testing
 @Suite
 struct HTTPServerTests {
     @Test
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testConsumingServe() async throws {
         let server = NIOHTTPServer(
             configuration: try .init(
diff --git a/Tests/NIOHTTPServerTests/ListenerConfigurationTests.swift b/Tests/NIOHTTPServerTests/ListenerConfigurationTests.swift
index d560145..551934a 100644
--- a/Tests/NIOHTTPServerTests/ListenerConfigurationTests.swift
+++ b/Tests/NIOHTTPServerTests/ListenerConfigurationTests.swift
@@ -18,7 +18,7 @@ import Testing
 
 @Suite
 struct ListenerConfigurationTests {
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("transport: plaintext, versions: {HTTP/1.1} -> plaintext")
     func plaintextHTTP1_1() throws {
         let configuration = try NIOHTTPServerConfiguration(
@@ -35,7 +35,7 @@ struct ListenerConfigurationTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "transport: TLS, versions: {HTTP/1.1 and/or HTTP/2} -> secure upgrade",
         arguments: [
@@ -66,7 +66,7 @@ struct ListenerConfigurationTests {
     }
 
     #if HTTP3
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("transport: TLS, versions: {HTTP/3} -> HTTP/3")
     func http3Only() throws {
         let chain = try TestCA.makeSelfSignedChain()
@@ -88,7 +88,7 @@ struct ListenerConfigurationTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "transport: TLS, versions: {HTTP/1.1 and/or HTTP/2} + {HTTP/3} -> HTTP/3 and secure upgrade",
         arguments: [
diff --git a/Tests/NIOHTTPServerTests/NIOHTTPServer+ServiceLifecycleTests.swift b/Tests/NIOHTTPServerTests/NIOHTTPServer+ServiceLifecycleTests.swift
index b97c220..c56227a 100644
--- a/Tests/NIOHTTPServerTests/NIOHTTPServer+ServiceLifecycleTests.swift
+++ b/Tests/NIOHTTPServerTests/NIOHTTPServer+ServiceLifecycleTests.swift
@@ -43,7 +43,7 @@ struct NIOHTTPServiceLifecycleTests {
         "Active connection completes when graceful shutdown triggered",
         arguments: [NIOHTTPServer.HTTPVersion.http1_1, .http2]
     )
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func activeConnectionCanCompleteWhenGracefullyShutdown(httpVersion: NIOHTTPServer.HTTPVersion) async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
             for: httpVersion,
@@ -126,7 +126,7 @@ struct NIOHTTPServiceLifecycleTests {
         "Server closes active connection upon forceful shutdown",
         arguments: [NIOHTTPServer.HTTPVersion.http1_1, .http2]
     )
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testServerClosesActiveConnectionOnForcefulShutdown(httpVersion: NIOHTTPServer.HTTPVersion) async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
             for: httpVersion,
@@ -200,7 +200,7 @@ struct NIOHTTPServiceLifecycleTests {
         "Active connection forcefully shutdown when server task cancelled",
         arguments: [NIOHTTPServer.HTTPVersion.http1_1, .http2]
     )
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func activeConnectionForcefullyShutdownWhenServerTaskCancelled(httpVersion: NIOHTTPServer.HTTPVersion) async throws
     {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
@@ -280,7 +280,7 @@ struct NIOHTTPServiceLifecycleTests {
     }
 
     @Test("Active HTTP/2 connection is forcefully shut down upon graceful shutdown timeout")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testActiveHTTP2ConnectionIsShutDownAfterGraceTimeout() async throws {
         let (leafPath, caPath, keyPath) = try TestCA.makeSelfSignedChain().writeToDisk()
 
@@ -368,7 +368,7 @@ struct NIOHTTPServiceLifecycleTests {
             (.http2, .http2),
         ]
     )
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func activeConnectionsAcrossDifferentListenersCanCompleteWhenGracefullyShutdown(
         firstClientHTTPVersion: NIOHTTPServer.HTTPVersion,
         secondClientHTTPVersion: NIOHTTPServer.HTTPVersion
diff --git a/Tests/NIOHTTPServerTests/NIOHTTPServerConfigurationTests.swift b/Tests/NIOHTTPServerTests/NIOHTTPServerConfigurationTests.swift
index 71484bf..8303113 100644
--- a/Tests/NIOHTTPServerTests/NIOHTTPServerConfigurationTests.swift
+++ b/Tests/NIOHTTPServerTests/NIOHTTPServerConfigurationTests.swift
@@ -24,7 +24,7 @@ import X509
 struct NIOHTTPServerConfigurationTests {
     @Suite
     struct BindTarget {
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         @Test("Empty bindTargets throws error")
         func emptyBindTargetsThrows() throws {
             #expect(throws: NIOHTTPServerConfigurationError.noBindTargetsSpecified) {
@@ -39,7 +39,7 @@ struct NIOHTTPServerConfigurationTests {
 
     @Suite
     struct SupportedHTTPVersions {
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         @Test("Empty supportedHTTPVersions throws error")
         func emptySupportedHTTPVersionsThrows() {
             #expect(throws: NIOHTTPServerConfigurationError.noSupportedHTTPVersionsSpecified) {
@@ -51,7 +51,7 @@ struct NIOHTTPServerConfigurationTests {
             }
         }
 
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         @Test("transport: plaintext, versions: {HTTP/1.1} -> valid")
         func plaintextTransportAndHTTP1_1IsValid() {
             #expect(throws: Never.self) {
@@ -64,7 +64,7 @@ struct NIOHTTPServerConfigurationTests {
         }
 
         #if HTTP3
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         @Test(
             "transport: plaintext, versions: HTTP/2 and/or HTTP/3 -> invalid",
             arguments: [
@@ -91,7 +91,7 @@ struct NIOHTTPServerConfigurationTests {
 
     @Suite
     struct TransportSecurity {
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         @Test(
             "All X.509 credential sources produce a valid configuration",
             arguments: TestX509CredentialSource.allCases
@@ -109,7 +109,7 @@ struct NIOHTTPServerConfigurationTests {
             }
         }
 
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         @Test("All mTLS trust root sources produce a valid configuration", arguments: MTLSTrustSource.allCases)
         func mTLSTrustRootSourceProducesValidConfiguration(source: MTLSTrustSource) throws {
             let chain = try TestCA.makeSelfSignedChain()
@@ -127,7 +127,7 @@ struct NIOHTTPServerConfigurationTests {
             }
         }
 
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         @Test(
             "A non-existent X.509 certificate file path is rejected",
             arguments: [
@@ -150,7 +150,7 @@ struct NIOHTTPServerConfigurationTests {
             }
         }
 
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         @Test(
             "Malformed X.509 credential bytes are rejected",
             arguments: [
@@ -174,7 +174,7 @@ struct NIOHTTPServerConfigurationTests {
         }
 
         #if HTTP3
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         @Test("PEM-file X.509 credentials over HTTP/3 produces a valid configuration")
         func pemFileX509ProducesValidHTTP3Configuration() throws {
             let chain = try TestCA.makeSelfSignedChain()
@@ -191,7 +191,7 @@ struct NIOHTTPServerConfigurationTests {
             }
         }
 
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         @Test(
             "Non-PEM-file X.509 credentials are rejected over HTTP/3",
             arguments: [TestX509CredentialSource.inMemory, .reloading, .pemBytes, .derFile, .derBytes]
@@ -209,7 +209,7 @@ struct NIOHTTPServerConfigurationTests {
             }
         }
 
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         @Test("DER-file RPK credentials produces a valid TLS configuration")
         func derFileRPKProducesValidConfiguration() throws {
             let chain = try TestCA.makeSelfSignedChain()
@@ -223,7 +223,7 @@ struct NIOHTTPServerConfigurationTests {
             }
         }
 
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         @Test("Raw public key credentials are rejected over HTTP/1.1 and HTTP/2")
         func rawPublicKeyRejectedOverHTTP1AndHTTP2() throws {
             #expect(
@@ -239,7 +239,7 @@ struct NIOHTTPServerConfigurationTests {
             }
         }
 
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         @Test("mTLS is rejected over HTTP/3")
         func mTLSRejectedOverHTTP3() throws {
             let chain = try TestCA.makeSelfSignedChain()
@@ -260,7 +260,7 @@ struct NIOHTTPServerConfigurationTests {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 enum TestX509CredentialSource: Sendable, CaseIterable {
     case inMemory
     case reloading
@@ -314,7 +314,7 @@ enum TestX509CredentialSource: Sendable, CaseIterable {
 }
 
 #if HTTP3
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.TransportSecurity.RawPublicKeyCredentials {
     /// Builds ``RawPublicKeyCredentials`` from `chain`.
     static func makeTestCredentials(
@@ -335,7 +335,7 @@ extension NIOHTTPServerConfiguration.TransportSecurity.RawPublicKeyCredentials {
 }
 #endif  // HTTP3
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 enum MTLSTrustSource: Sendable, CaseIterable {
     case systemDefaults
     case inMemory
diff --git a/Tests/NIOHTTPServerTests/NIOHTTPServerEndToEndTests.swift b/Tests/NIOHTTPServerTests/NIOHTTPServerEndToEndTests.swift
index 42953a9..8d3a6d3 100644
--- a/Tests/NIOHTTPServerTests/NIOHTTPServerEndToEndTests.swift
+++ b/Tests/NIOHTTPServerTests/NIOHTTPServerEndToEndTests.swift
@@ -21,7 +21,7 @@ import Testing
 
 @Suite
 struct NIOHTTPServerEndToEndTests {
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("HTTP/1.1 request and response")
     func testHTTP1_1() async throws {
         try await TestingChannelHTTP1Server.serve(
@@ -48,7 +48,7 @@ struct NIOHTTPServerEndToEndTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("HTTP/2 negotiation")
     func testHTTP2Negotiation() async throws {
         let serverChain = try TestCA.makeSelfSignedChain()
diff --git a/Tests/NIOHTTPServerTests/NIOHTTPServerReaderTests.swift b/Tests/NIOHTTPServerTests/NIOHTTPServerReaderTests.swift
index 5d1f038..e7711dc 100644
--- a/Tests/NIOHTTPServerTests/NIOHTTPServerReaderTests.swift
+++ b/Tests/NIOHTTPServerTests/NIOHTTPServerReaderTests.swift
@@ -29,7 +29,7 @@ import NIOHTTP3
 @Suite
 struct NIOHTTPServerReaderTests {
     @Test("Head request not allowed")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testWriteHeadRequestPartFatalError() async throws {
         // The request body reader should fatal error if it receives a head part
         await #expect(processExitsWith: .failure) {
@@ -48,7 +48,7 @@ struct NIOHTTPServerReaderTests {
     }
 
     @Test("Stream cannot be finished before writing request end part")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testNotWritingRequestEndPartFatalError() async throws {
         await #expect(processExitsWith: .failure) {
             let (stream, source) = NIOAsyncChannelInboundStream<HTTPRequestPart>.makeTestingStream()
@@ -75,7 +75,7 @@ struct NIOHTTPServerReaderTests {
             HTTPFields([.init(name: .cookie, value: "first_cookie"), .init(name: .cookie, value: "second_cookie")]),
         ]
     )
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testRequestWithConcludingElement(body: ByteBuffer, trailers: HTTPFields) async throws {
         let (stream, source) = NIOAsyncChannelInboundStream<HTTPRequestPart>.makeTestingStream()
 
@@ -108,7 +108,7 @@ struct NIOHTTPServerReaderTests {
             HTTPFields([.init(name: .cookie, value: "first_cookie"), .init(name: .cookie, value: "second_cookie")]),
         ]
     )
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testStreamedRequestBody(bodyChunks: [ByteBuffer], trailers: HTTPFields) async throws {
         let (stream, source) = NIOAsyncChannelInboundStream<HTTPRequestPart>.makeTestingStream()
 
@@ -144,7 +144,7 @@ struct NIOHTTPServerReaderTests {
     }
 
     @Test("Throw while reading request")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testThrowingWhileReadingRequest() async throws {
         let (stream, source) = NIOAsyncChannelInboundStream<HTTPRequestPart>.makeTestingStream()
 
@@ -171,7 +171,7 @@ struct NIOHTTPServerReaderTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("More bytes available than consumption limit")
     func testCollectMoreBytesThanAvailable() async throws {
         let (stream, source) = NIOAsyncChannelInboundStream<HTTPRequestPart>.makeTestingStream()
@@ -212,7 +212,7 @@ struct NIOHTTPServerReaderTests {
 
     #if HTTP3 && UnstableHTTPDatagrams
     @Test("takeDatagramReader vends no datagram reader when not available")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func takeDatagramReaderVendsNilWhenNotAvailable() async throws {
         let (stream, source) = NIOAsyncChannelInboundStream<HTTPRequestPart>.makeTestingStream()
         source.yield(.body(ByteBuffer(bytes: [1, 2, 3])))
@@ -237,7 +237,7 @@ struct NIOHTTPServerReaderTests {
     }
 
     @Test("takeDatagramReader vends a request body and datagram reader")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func takeDatagramReaderVendsRequestAndDatagramReader() async throws {
         let (reliableStream, reliableSource) = NIOAsyncChannelInboundStream<HTTPRequestPart>.makeTestingStream()
         reliableSource.yield(.body(ByteBuffer(bytes: [1, 2, 3])))
@@ -294,7 +294,7 @@ struct NIOHTTPServerReaderTests {
     }
 
     @Test("Inbound datagrams are buffered up to a limit", arguments: [10, 20, 100])
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func datagramsAreBufferedUpToLimit(maxBufferedDatagrams: Int) async throws {
         let (reliableStream, _) = NIOAsyncChannelInboundStream<HTTPRequestPart>.makeTestingStream()
 
diff --git a/Tests/NIOHTTPServerTests/NIOHTTPServerResponseSenderTests.swift b/Tests/NIOHTTPServerTests/NIOHTTPServerResponseSenderTests.swift
index e7403ed..2e38121 100644
--- a/Tests/NIOHTTPServerTests/NIOHTTPServerResponseSenderTests.swift
+++ b/Tests/NIOHTTPServerTests/NIOHTTPServerResponseSenderTests.swift
@@ -22,7 +22,7 @@ import Testing
 @Suite
 struct NIOHTTPServerResponseSenderTests {
     @Test("Informational header without informational status code")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testInformationalResponseStatusCodePrecondition() async throws {
         // Sending an informational header with a non-1xx status code shouldn't be allowed
         try await #require(processExitsWith: .failure) {
@@ -34,7 +34,7 @@ struct NIOHTTPServerResponseSenderTests {
     }
 
     @Test("Multiple informational responses before final response")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testSendMultipleInformationalResponses() async throws {
         let (outboundWriter, sink) = NIOAsyncChannelOutboundWriter<HTTPResponsePart>.makeTestingWriter()
         var sender = NIOHTTPServer.ResponseSender(writer: outboundWriter, writerState: .init())
diff --git a/Tests/NIOHTTPServerTests/NIOHTTPServerStreamResetTests.swift b/Tests/NIOHTTPServerTests/NIOHTTPServerStreamResetTests.swift
index 1b535e8..cd90004 100644
--- a/Tests/NIOHTTPServerTests/NIOHTTPServerStreamResetTests.swift
+++ b/Tests/NIOHTTPServerTests/NIOHTTPServerStreamResetTests.swift
@@ -52,7 +52,7 @@ struct NIOHTTPServerStreamResetTests {
     // MARK: - HTTP/1.1
 
     @Test("Aborting while the response head is still buffered flushes it with Connection: close and no response end")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testHTTP1AbortWhileResponseHeadIsBuffered() throws {
         let channel = EmbeddedChannel()
         try channel.connect(to: try .init(ipAddress: "127.0.0.1", port: 0)).wait()
@@ -96,7 +96,7 @@ struct NIOHTTPServerStreamResetTests {
     }
 
     @Test("Aborting after the response head reached the wire sends no second head and no response end")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testHTTP1AbortWhileStreaming() throws {
         let channel = EmbeddedChannel()
         try channel.connect(to: try .init(ipAddress: "127.0.0.1", port: 0)).wait()
@@ -137,7 +137,7 @@ struct NIOHTTPServerStreamResetTests {
         "HTTP/1.1: throwing before the response head sends 500 with Connection: close",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1]
     )
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testHTTP1ThrowingBeforeResponseHeadSendsInternalServerError(
         http1Variant: NIOHTTPServer.HTTPVersion
     ) async throws {
@@ -174,7 +174,7 @@ struct NIOHTTPServerStreamResetTests {
     // MARK: - HTTP/2
 
     @Test("HTTP/2: throwing a conforming error resets the stream with that error's code")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testHTTP2ThrowingConformingErrorResetsStream() async throws {
         try await self.assertHTTP2Reset(
             throwing: StreamResetTestError.connectFailed,
@@ -183,7 +183,7 @@ struct NIOHTTPServerStreamResetTests {
     }
 
     @Test("HTTP/2: throwing a non-conforming error resets the stream with INTERNAL_ERROR")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testHTTP2ThrowingNonConformingErrorResetsStreamWithInternalError() async throws {
         try await self.assertHTTP2Reset(
             throwing: TestError.intentional,
@@ -192,7 +192,7 @@ struct NIOHTTPServerStreamResetTests {
     }
 
     /// Runs a handler that throws `error` over HTTP/2 and asserts the client observes `RST_STREAM(expectedCode)`.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     private func assertHTTP2Reset(
         throwing error: any Error,
         expectedCode: NIOHTTP2.HTTP2ErrorCode,
@@ -239,7 +239,7 @@ struct NIOHTTPServerStreamResetTests {
     }
 
     @Test("HTTP/2: throwing after the response head still resets the stream")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testHTTP2ThrowingAfterResponseHeadResetsStream() async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
             for: .http2,
@@ -296,7 +296,7 @@ struct NIOHTTPServerStreamResetTests {
     // MARK: - HTTP/3
 
     @Test("Aborting an HTTP/3 stream emits RESET_STREAM and STOP_SENDING carrying the resolved codes")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testHTTP3AbortEmitsResetStreamAndStopSending() throws {
         let channel = EmbeddedChannel()
         try channel.connect(to: try .init(ipAddress: "127.0.0.1", port: 0)).wait()
@@ -323,7 +323,7 @@ struct NIOHTTPServerStreamResetTests {
     }
 
     @Test("Aborting an HTTP/3 stream with an error describing no codes uses H3_INTERNAL_ERROR")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testHTTP3AbortWithNonConformingErrorUsesInternalError() throws {
         let channel = EmbeddedChannel()
         try channel.connect(to: try .init(ipAddress: "127.0.0.1", port: 0)).wait()
@@ -344,7 +344,7 @@ struct NIOHTTPServerStreamResetTests {
     }
 
     @Test("HTTP/3: throwing from the handler resets the stream, failing the client's read")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testHTTP3ThrowingResetsStream() async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
             for: .http3,
@@ -372,7 +372,7 @@ struct NIOHTTPServerStreamResetTests {
         #expect(httpError.h3ErrorCode == .connectError)
     }
     @Test("HTTP/3: throwing after the response head still resets the stream")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testHTTP3ThrowingAfterResponseHeadResetsStream() async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
             for: .http3,
@@ -409,7 +409,7 @@ struct NIOHTTPServerStreamResetTests {
         "Throwing after the response is concluded still delivers the full response",
         arguments: NIOHTTPServer.HTTPVersion.allCases
     )
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testThrowingAfterConcludedResponseDeliversFullResponse(
         httpVersion: NIOHTTPServer.HTTPVersion
     ) async throws {
diff --git a/Tests/NIOHTTPServerTests/NIOHTTPServerSwiftConfigurationTests.swift b/Tests/NIOHTTPServerTests/NIOHTTPServerSwiftConfigurationTests.swift
index fd070cc..5b7948a 100644
--- a/Tests/NIOHTTPServerTests/NIOHTTPServerSwiftConfigurationTests.swift
+++ b/Tests/NIOHTTPServerTests/NIOHTTPServerSwiftConfigurationTests.swift
@@ -28,7 +28,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
     @Suite("BindTarget")
     struct BindTargetTests {
         @Test("Valid host and port")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testValidConfig() throws {
             let provider = InMemoryProvider(values: ["host": "localhost", "port": 8080])
 
@@ -45,7 +45,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("Init fails with missing host")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testMissingHost() throws {
             let provider = InMemoryProvider(values: ["port": 8080])
             let config = ConfigReader(provider: provider)
@@ -59,7 +59,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("Init fails with missing port")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testMissingPort() throws {
             let provider = InMemoryProvider(values: ["host": "localhost"])
             let config = ConfigReader(provider: provider)
@@ -76,7 +76,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
     @Suite("Multiple bind targets via bindTargets")
     struct MultipleBindTargetsTests {
         @Test("Parallel hosts and ports produce multiple bind targets")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testMultipleBindTargets() throws {
             let provider = InMemoryProvider(
                 values: [
@@ -107,7 +107,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("Singular bindTarget still works")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testSingularBindTargetStillWorks() throws {
             let provider = InMemoryProvider(
                 values: [
@@ -131,7 +131,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("Providing both singular and plural throws an error")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testBothSingularAndPluralThrows() throws {
             let provider = InMemoryProvider(
                 values: [
@@ -151,7 +151,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("Mismatched hosts and ports lengths throws an error")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testMismatchedHostsAndPortsLengthsThrows() throws {
             let provider = InMemoryProvider(
                 values: [
@@ -169,7 +169,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("Empty bindTargets arrays throws an error")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testEmptyBindTargetsArraysThrows() throws {
             let provider = InMemoryProvider(
                 values: [
@@ -190,7 +190,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
     @Suite("BackPressureStrategy")
     struct BackPressureStrategyTests {
         @Test("Default values")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testDefaultValues() throws {
             // Don't provide anything. All values have defaults.
             let provider = InMemoryProvider(values: [:])
@@ -207,7 +207,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("Custom values")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testCustomValues() throws {
             let provider = InMemoryProvider(values: ["lowWatermark": 5, "highWatermark": 20])
             let config = ConfigReader(provider: provider)
@@ -223,7 +223,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("Partial custom values")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testPartialCustomValues() throws {
             let provider = InMemoryProvider(values: ["lowWatermark": 3])
             let config = ConfigReader(provider: provider)
@@ -242,7 +242,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
     @Suite("SupportedHTTPVersions")
     struct SupportedHTTPVersionsTests {
         @Test("Empty supported version set is invalid")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testEmptySupportedHTTPVersionSetFails() async {
             await #expect(processExitsWith: .failure) {
                 let provider = InMemoryProvider(values: [
@@ -256,7 +256,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("Unrecognized versions are ignored")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testUnrecognizedHTTPVersionIgnored() throws {
             let provider = InMemoryProvider(values: [
                 "versions": .init(.stringArray(["unrecognized_version"]), isSecret: false)
@@ -273,7 +273,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("Default HTTP/2 configuration used when not specified")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testDefaultHTTP2ConfigurationUsed() throws {
             let provider = InMemoryProvider(values: [
                 "versions": .init(.stringArray(["http1_1", "http2"]), isSecret: false)
@@ -288,7 +288,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
 
         #if HTTP3
         @Test("Default HTTP/3 configuration used when not specified")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func defaultHTTP3ConfigurationUsed() throws {
             let versions = ConfigValue(.stringArray(["http1_1", "http3"]), isSecret: false)
             let snapshot = ConfigReader(provider: InMemoryProvider(values: ["versions": versions])).snapshot()
@@ -303,7 +303,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
     @Suite("HTTP2")
     struct HTTP2Tests {
         @Test("Default values")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testDefaultValues() throws {
             let provider = InMemoryProvider(values: [:])
             let config = ConfigReader(provider: provider)
@@ -317,7 +317,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("Custom values")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testCustomValues() throws {
             let provider = InMemoryProvider(values: [
                 "maxFrameSize": 1,
@@ -335,7 +335,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("Partial custom values")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testPartialCustomValues() throws {
             let provider = InMemoryProvider(values: ["maxFrameSize": 5])
             let config = ConfigReader(provider: provider)
@@ -353,7 +353,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
     @Suite("HTTP3")
     struct HTTP3Tests {
         @Test("Default values")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func defaultValues() throws {
             let snapshot = ConfigReader(provider: InMemoryProvider(values: [:])).snapshot()
 
@@ -363,7 +363,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("Custom values")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func customValues() throws {
             let provider = InMemoryProvider(values: [
                 "preferHuffmanEncoding": false,
@@ -425,7 +425,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         @Suite("ConnectionSettings")
         struct ConnectionSettingsTests {
             @Test("Default values")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func defaultValues() {
                 let snapshot = ConfigReader(provider: InMemoryProvider(values: [:])).snapshot()
 
@@ -438,7 +438,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Custom values")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func customValues() {
                 let snapshot = ConfigReader(
                     provider: InMemoryProvider(values: [
@@ -456,7 +456,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Negative values resolve to valid values")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func negativeClampsResolveToValidValues() {
                 let snapshot = ConfigReader(
                     provider: InMemoryProvider(values: [
@@ -478,7 +478,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         @Suite("DatagramConfiguration")
         struct DatagramConfigurationTests {
             @Test("Default values")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func defaultValues() throws {
                 let snapshot = ConfigReader(provider: InMemoryProvider(values: [:])).snapshot()
 
@@ -488,7 +488,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Custom values")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func customValues() throws {
                 let snapshot = ConfigReader(
                     provider: InMemoryProvider(values: [
@@ -506,7 +506,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Datagrams configuration `nil` when `datagramsEnabled` set to false")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func configNilWhenDatagramsEnabledSetToFalse() throws {
                 let snapshot = ConfigReader(
                     provider: InMemoryProvider(values: [
@@ -518,7 +518,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Maximum frame size must not be set to 0 when datagrams enabled")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func frameSizeMustNotBeZeroWhenDatagramsEnabled() async throws {
                 await #expect(processExitsWith: .failure) {
                     // Setting `maxDatagramFrameSize` to 0 means that the QUIC layer will not advertise support for
@@ -540,7 +540,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         @Suite("QUICConfiguration")
         struct QUICConfigurationTests {
             @Test("Default values")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func defaultValues() throws {
                 let snapshot = ConfigReader(provider: InMemoryProvider(values: [:])).snapshot()
 
@@ -550,7 +550,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Durations are extracted as seconds")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func durationsExtractedAsSeconds() throws {
                 let snapshot = ConfigReader(
                     provider: InMemoryProvider(values: ["maxIdleTimeout": 45, "keepAliveInterval": 5])
@@ -563,7 +563,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Invalid key exchange group throws")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func invalidKeyExchangeGroup() throws {
                 let snapshot = ConfigReader(provider: InMemoryProvider(values: ["keyExchangeGroup": "<not_a_group>"]))
                     .snapshot()
@@ -582,7 +582,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         @Suite("QLogConfiguration")
         struct QLogConfigurationTests {
             @Test("No qlog configuration specified")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func valuesNotSpecified() throws {
                 let snapshot = ConfigReader(provider: InMemoryProvider(values: [:])).snapshot()
 
@@ -592,7 +592,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Fully specified qlog configuration")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func allValuesSpecified() throws {
                 let snapshot = ConfigReader(
                     provider: InMemoryProvider(values: [
@@ -610,7 +610,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Partial qlog configuration is invalid")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func partialConfigurationInvalid() throws {
                 let snapshot = ConfigReader(provider: InMemoryProvider(values: ["qlog.path": "/var/log/qlog"]))
                     .snapshot()
@@ -624,7 +624,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("End-to-end HTTP/3 configuration over TLS")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testEndToEnd() throws {
             let (leafPath, _, keyPath) = try TestCA.makeSelfSignedChain().writeToDisk()
             let provider = InMemoryProvider(values: [
@@ -656,7 +656,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
     @Suite("TransportSecurity")
     struct TransportSecurityTests {
         @Test("Invalid security mode")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testInvalidSecurityMode() throws {
             let provider = InMemoryProvider(values: ["mode": "<this_mode_does_not_exist>"])
             let config = ConfigReader(provider: provider)
@@ -670,7 +670,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("Custom verification callback without mTLS being enabled")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func testCannotInitializeWithCustomCallbackWhenMTLSNotEnabled() throws {
             let provider = InMemoryProvider(values: ["mode": "tls", "credentialSource": "inline"])
             let config = ConfigReader(provider: provider)
@@ -695,7 +695,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         @Suite
         struct TLS {
             @Test("Valid config using inline credentials")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func testValidConfigUsingInlineCredentials() throws {
                 let chain = try TestCA.makeSelfSignedChain()
                 let certsPEM = try chain.chainPEMString
@@ -731,7 +731,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Valid file-based credentials with reloading")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func testValidFileConfigWithReloading() async throws {
                 let provider = InMemoryProvider(
                     values: [
@@ -761,7 +761,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Valid file-based credentials without reloading")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func testValidFileConfigWithoutReloading() throws {
                 let provider = InMemoryProvider(
                     values: [
@@ -791,7 +791,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
 
             #if HTTP3
             @Test("Raw public key credentials")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func testRawPublicKeyCredentials() throws {
                 let provider = InMemoryProvider(
                     values: [
@@ -826,7 +826,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             #endif  // HTTP3
 
             @Test("Init fails with missing certificate")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func testMissingCertificate() throws {
                 let chain = try TestCA.makeSelfSignedChain()
                 let keyPEM = try chain.privateKey.serializeAsPEM().pemString
@@ -849,7 +849,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Init fails with missing private key")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func testMissingPrivateKey() throws {
                 let chain = try TestCA.makeSelfSignedChain()
                 let certsPEM = try chain.chainPEMString
@@ -875,7 +875,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         @Suite
         struct MTLS {
             @Test("Custom verification callback")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func testValidConfigWithCustomVerificationCallback() throws {
                 let serverChain = try TestCA.makeSelfSignedChain()
 
@@ -929,7 +929,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Optional verification mode")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func testOptionalVerification() throws {
                 let serverChain = try TestCA.makeSelfSignedChain()
                 let certsPEM = try serverChain.chainPEMString
@@ -975,7 +975,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Invalid verification mode")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func testInvalidVerificationMode() throws {
                 let serverChain = try TestCA.makeSelfSignedChain()
 
@@ -1006,7 +1006,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Default trust roots")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func testDefaultTrustRoots() throws {
                 let serverChain = try TestCA.makeSelfSignedChain()
 
@@ -1052,7 +1052,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             }
 
             @Test("Trust roots from PEM file path")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func testTrustRootsFromPEMFilePath() throws {
                 let serverChain = try TestCA.makeSelfSignedChain()
 
@@ -1095,7 +1095,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         @Suite
         struct ReloadingMTLS {
             @Test("Valid config with file credentials and reloading")
-            @available(anyAppleOS 26.0, *)
+            @available(anyAppleOS 27.0, *)
             func testValidConfig() async throws {
                 let chain = try TestCA.makeSelfSignedChain()
                 let trustRootPEM = try chain.ca.serializeAsPEM().pemString
@@ -1142,7 +1142,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
 
     @Suite("GracefulShutdownConfiguration")
     struct GracefulShutdownConfigurationTests {
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         @Test("Default value") func defaultValue() {
             let provider = InMemoryProvider(values: [:])
             let config = ConfigReader(provider: provider)
@@ -1154,7 +1154,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
             #expect(gracefulShutdown.maximumGracefulShutdownDuration == nil)
         }
 
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         @Test("Custom value") func customValue() {
             let provider = InMemoryProvider(values: ["maximumDuration": 42])
             let config = ConfigReader(provider: provider)
@@ -1169,7 +1169,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
     @Suite("End-to-End")
     struct EndToEndConfigurationTests {
         @Test("Configure all possible values")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func fullConfiguration() throws {
             let chain = try TestCA.makeSelfSignedChain()
             let certsPEM = try chain.chainPEMString
@@ -1238,7 +1238,7 @@ struct NIOHTTPServerSwiftConfigurationTests {
         }
 
         @Test("Only HTTP/1.1 supported over plaintext")
-        @available(anyAppleOS 26.0, *)
+        @available(anyAppleOS 27.0, *)
         func onlyHTTP1_1SupportedOverPlaintext() async {
             await #expect(processExitsWith: .failure) {
                 let provider = InMemoryProvider(
diff --git a/Tests/NIOHTTPServerTests/NIOHTTPServerTests.swift b/Tests/NIOHTTPServerTests/NIOHTTPServerTests.swift
index 0499cc5..2828159 100644
--- a/Tests/NIOHTTPServerTests/NIOHTTPServerTests.swift
+++ b/Tests/NIOHTTPServerTests/NIOHTTPServerTests.swift
@@ -40,7 +40,7 @@ struct NIOHTTPServerTests {
     let clientLogger = Logger(label: "NIOHTTPServerTests.client")
     let serverLogger = Logger(label: "NIOHTTPServerTests.server")
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("Obtain the listening address correctly")
     func testListeningAddress() async throws {
         let server = NIOHTTPServer(
@@ -68,7 +68,7 @@ struct NIOHTTPServerTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("Request-response", arguments: NIOHTTPServer.HTTPVersion.allCases)
     func testRequestResponse(httpVersion: NIOHTTPServer.HTTPVersion) async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
@@ -118,7 +118,7 @@ struct NIOHTTPServerTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "mTLS request-response with custom verification callback returning peer certificates",
         arguments: [NIOHTTPServer.HTTPVersion.http1_1, .http2]
@@ -181,7 +181,7 @@ struct NIOHTTPServerTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("Multiple informational response headers", arguments: NIOHTTPServer.HTTPVersion.allCases)
     func testMultipleInformationalResponseHeaders(httpVersion: NIOHTTPServer.HTTPVersion) async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
@@ -223,7 +223,7 @@ struct NIOHTTPServerTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "Client closes stream without sending end part",
         arguments: [NIOHTTPServer.HTTPVersion.http1_1, .http2]
@@ -273,7 +273,7 @@ struct NIOHTTPServerTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("Bi-directional streaming", arguments: [NIOHTTPServer.HTTPVersion.http1_1, .http2])
     func testBidirectionalStreaming(httpVersion: NIOHTTPServer.HTTPVersion) async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
@@ -332,7 +332,7 @@ struct NIOHTTPServerTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "Multiple serial HTTP/1.1 requests on the same connection",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1]
@@ -379,7 +379,7 @@ struct NIOHTTPServerTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("Multiple concurrent connections", arguments: NIOHTTPServer.HTTPVersion.allCases)
     func testMultipleConcurrentConnections(httpVersion: NIOHTTPServer.HTTPVersion) async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
@@ -442,7 +442,7 @@ struct NIOHTTPServerTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     #if HTTP3
     @Test("Multiple concurrent streams over single connection", arguments: [NIOHTTPServer.HTTPVersion.http2, .http3])
     #else
@@ -504,7 +504,7 @@ struct NIOHTTPServerTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "Server can still process other connections despite one failing",
         arguments: [NIOHTTPServer.HTTPVersion.plaintextHTTP1_1, .http1_1, .http2]
@@ -569,7 +569,7 @@ struct NIOHTTPServerTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("Bind to multiple addresses")
     func testMultipleBindAddresses() async throws {
         let server = NIOHTTPServer(
@@ -594,7 +594,7 @@ struct NIOHTTPServerTests {
         )
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("Serve requests on multiple addresses independently", arguments: NIOHTTPServer.HTTPVersion.allCases)
     func testServeOnMultipleAddresses(httpVersion: NIOHTTPServer.HTTPVersion) async throws {
         let (server, clientConfiguration) = try TestHelpers.makeServerAndClientConfiguration(
@@ -642,7 +642,7 @@ struct NIOHTTPServerTests {
     /// all bound addresses become unavailable simultaneously and ``listeningAddresses`` throws
     /// ``ListeningAddressError/serverClosed``. No subset of addresses continues serving after the server
     /// has stopped.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "All addresses stop together and listeningAddresses throws after server stops",
         arguments: NIOHTTPServer.HTTPVersion.allCases
@@ -694,7 +694,7 @@ struct NIOHTTPServerTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("Empty bind targets throws error")
     func testEmptyBindTargetsThrows() throws {
         #expect(throws: NIOHTTPServerConfigurationError.noBindTargetsSpecified) {
@@ -719,7 +719,7 @@ struct NIOHTTPServerTests {
     /// to for the verification. The port is below the typical ephemeral range used by `port: 0`
     /// allocations on Linux (32768+) and macOS (49152+), so other tests using `port: 0` cannot
     /// accidentally be assigned this port by the OS.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("Previously bound channels are closed when a later bind fails")
     func testPreviouslyBoundChannelsAreClosedOnPartialBindFailure() async throws {
         let firstPort = 30_210
diff --git a/Tests/NIOHTTPServerTests/NIOHTTPServerWriterTests.swift b/Tests/NIOHTTPServerTests/NIOHTTPServerWriterTests.swift
index 374ca4b..00e4c5b 100644
--- a/Tests/NIOHTTPServerTests/NIOHTTPServerWriterTests.swift
+++ b/Tests/NIOHTTPServerTests/NIOHTTPServerWriterTests.swift
@@ -33,7 +33,7 @@ struct NIOHTTPServerWriterTests {
     let trailerSampleTwo: HTTPFields = [.serverTiming: "test", .cookie: "cookie"]
 
     @Test("Write single body element")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testSingleWriteAndConclude() async throws {
         let (writer, sink) = NIOAsyncChannelOutboundWriter<HTTPResponsePart>.makeTestingWriter()
         let responseWriter = NIOHTTPServer.ResponseSender.Writer(writer: writer, writerState: .init())
@@ -52,7 +52,7 @@ struct NIOHTTPServerWriterTests {
     }
 
     @Test("Write multiple body elements")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testProduceMultipleElementsAndSingleTrailer() async throws {
         let (writer, sink) = NIOAsyncChannelOutboundWriter<HTTPResponsePart>.makeTestingWriter()
         var responseWriter = NIOHTTPServer.ResponseSender.Writer(writer: writer, writerState: .init())
@@ -75,7 +75,7 @@ struct NIOHTTPServerWriterTests {
     }
 
     @Test("No body, just trailers")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func testNoBodyJustTrailers() async throws {
         let (writer, sink) = NIOAsyncChannelOutboundWriter<HTTPResponsePart>.makeTestingWriter()
         let responseWriter = NIOHTTPServer.ResponseSender.Writer(writer: writer, writerState: .init())
@@ -89,7 +89,7 @@ struct NIOHTTPServerWriterTests {
 
     #if HTTP3 && UnstableHTTPDatagrams
     @Test("takeDatagramWriter vends no datagram writer when not available")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func takeDatagramWriterVendsNilWhenNotAvailable() async throws {
         let (outboundWriter, sink) = NIOAsyncChannelOutboundWriter<HTTPResponsePart>.makeTestingWriter()
         let sender = NIOHTTPServer.ResponseSender(
@@ -120,7 +120,7 @@ struct NIOHTTPServerWriterTests {
     }
 
     @Test("takeDatagramWriter vends a response body and datagram writer")
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     func takeDatagramWriterVendsResponseAndDatagramWriter() async throws {
         let (outboundWriter, sink) = NIOAsyncChannelOutboundWriter<HTTPResponsePart>.makeTestingWriter()
         let connectionChannel = EmbeddedChannel()
diff --git a/Tests/NIOHTTPServerTests/QUICDatagramSocketGroupTests.swift b/Tests/NIOHTTPServerTests/QUICDatagramSocketGroupTests.swift
index 819d4e0..816b9f6 100644
--- a/Tests/NIOHTTPServerTests/QUICDatagramSocketGroupTests.swift
+++ b/Tests/NIOHTTPServerTests/QUICDatagramSocketGroupTests.swift
@@ -37,7 +37,7 @@ extension Trait where Self == ConditionTrait {
 struct QUICDatagramSocketGroupTests {
     let serverLogger = Logger(label: "QUICDatagramSocketGroupTests.server")
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "Every socket in the group is bound once, with indices from zero, each on its own event loop",
         .requiresSeveralEventLoops
@@ -61,7 +61,7 @@ struct QUICDatagramSocketGroupTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("Multiple HTTP/3 sockets per bind target report one address each", .requiresSeveralEventLoops)
     func testMultipleHTTP3SocketsPerBindTargetReportOneAddressEach() async throws {
         let factory = QUICDatagramSocketGroupFactory { _, _ in RecordingSocketGroup(socketCount: 2) }
@@ -75,7 +75,7 @@ struct QUICDatagramSocketGroupTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("A group of one socket is still told it bound and still vends its generator")
     func testGroupOfOneSocketIsToldItBoundAndVendsItsGenerator() async throws {
         let socketGroup = RecordingSocketGroup(socketCount: 1)
@@ -95,7 +95,7 @@ struct QUICDatagramSocketGroupTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("Each bind target gets its own socket group", .requiresSeveralEventLoops)
     func testEachBindTargetGetsItsOwnSocketGroup() async throws {
         let socketGroups = Mutex<[RecordingSocketGroup]>([])
@@ -114,7 +114,7 @@ struct QUICDatagramSocketGroupTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("A group need implement only the bound-socket hook", .requiresSeveralEventLoops)
     func testGroupNeedImplementOnlyTheBoundSocketHook() async throws {
         let factory = QUICDatagramSocketGroupFactory { _, _ in MinimalSocketGroup() }
@@ -124,7 +124,7 @@ struct QUICDatagramSocketGroupTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("Bind targets without a socket group spread across event loops", .requiresSeveralEventLoops)
     func testBindTargetsWithoutASocketGroupSpreadAcrossEventLoops() throws {
         let (configuration, _) = try TestHelpers.makeTLSServerConfiguration(
@@ -143,7 +143,7 @@ struct QUICDatagramSocketGroupTests {
         #expect(first.eventLoops[0] !== second.eventLoops[0])
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("A socket count outside the available event loops fails server bootstrap")
     func testSocketCountOutsideAvailableEventLoopsFailsServerStart() throws {
         let (configuration, _) = try TestHelpers.makeTLSServerConfiguration(
@@ -166,7 +166,7 @@ struct QUICDatagramSocketGroupTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("A factory that declines binds a single socket")
     func testDecliningFactoryBindsASingleSocket() async throws {
         let availableEventLoops = Mutex(0)
@@ -182,7 +182,7 @@ struct QUICDatagramSocketGroupTests {
         #expect(availableEventLoops.withLock { $0 } == NIOSingletons.groupLoopCountSuggestion)
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test("A factory that throws fails server bootstrap")
     func testThrowingFactoryFailsServerStart() async throws {
         let factory = QUICDatagramSocketGroupFactory { _, _ in throw SocketGroupTestError() }
@@ -192,7 +192,7 @@ struct QUICDatagramSocketGroupTests {
         }
     }
 
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     @Test(
         "A socket group that throws in bind callback fails server bootstrap",
         .requiresSeveralEventLoops,
@@ -210,7 +210,7 @@ struct QUICDatagramSocketGroupTests {
 
     /// Serves HTTP/3 on `bindTargetCount` ephemeral ports with `socketGroupFactory`, runs `body` with the
     /// listening addresses, then cancels the server.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     private func withHTTP3Server(
         bindTargetCount: Int = 1,
         socketGroupFactory: QUICDatagramSocketGroupFactory,
@@ -236,7 +236,7 @@ struct QUICDatagramSocketGroupTests {
 struct SocketGroupTestError: Error {}
 
 /// A group implementing only the protocol's requirements, using the default implementations of other methods.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 final class MinimalSocketGroup: QUICDatagramSocketGroup {
     let socketCount = 2
 
@@ -244,7 +244,7 @@ final class MinimalSocketGroup: QUICDatagramSocketGroup {
 }
 
 /// A socket group that records what the server asked it to do.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 final class RecordingSocketGroup: QUICDatagramSocketGroup {
     let socketCount: Int
 
diff --git a/Tests/NIOHTTPServerTests/Utilities/Certificates.swift b/Tests/NIOHTTPServerTests/Utilities/Certificates.swift
index 7146e57..c0cc2d3 100644
--- a/Tests/NIOHTTPServerTests/Utilities/Certificates.swift
+++ b/Tests/NIOHTTPServerTests/Utilities/Certificates.swift
@@ -19,7 +19,7 @@ import X509
 
 @testable import NIOHTTPServer
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct ChainPrivateKeyPair {
     let leaf: Certificate
     let ca: Certificate
@@ -60,7 +60,7 @@ struct ChainPrivateKeyPair {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct TestCA {
     static func makeSelfSignedChain(leafExtensions: Certificate.Extensions = .init()) throws -> ChainPrivateKeyPair {
         let caKey = P384.Signing.PrivateKey()
diff --git a/Tests/NIOHTTPServerTests/Utilities/HTTPVersion.swift b/Tests/NIOHTTPServerTests/Utilities/HTTPVersion.swift
index 116f709..f786c8e 100644
--- a/Tests/NIOHTTPServerTests/Utilities/HTTPVersion.swift
+++ b/Tests/NIOHTTPServerTests/Utilities/HTTPVersion.swift
@@ -14,7 +14,7 @@
 
 import NIOHTTPServer
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer.HTTPVersion {
     /// The ALPN protocol identifier.
     ///
@@ -38,7 +38,7 @@ extension NIOHTTPServer.HTTPVersion {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServerConfiguration.HTTPVersion {
     init(_ version: NIOHTTPServer.HTTPVersion) {
         switch version {
diff --git a/Tests/NIOHTTPServerTests/Utilities/Helpers.swift b/Tests/NIOHTTPServerTests/Utilities/Helpers.swift
index ff113b3..3a91472 100644
--- a/Tests/NIOHTTPServerTests/Utilities/Helpers.swift
+++ b/Tests/NIOHTTPServerTests/Utilities/Helpers.swift
@@ -106,7 +106,7 @@ extension TLSConfiguration {
     }
 
     /// Like ``makeTestClientConfiguration``, but with mTLS.
-    @available(anyAppleOS 26.0, *)
+    @available(anyAppleOS 27.0, *)
     static func makeTestClientMTLSConfiguration(
         testTrustRoots: NIOSSLTrustRoots,
         clientChain: ChainPrivateKeyPair,
@@ -124,7 +124,7 @@ extension TLSConfiguration {
 }
 
 #if HTTP3
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension QUICConfiguration {
     /// Creates a client QUIC configuration.
     ///
@@ -144,7 +144,7 @@ extension QUICConfiguration {
 }
 #endif
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct TestHelpers {
     /// Starts `server` with `serverHandler`, waits for it to begin listening, runs `body` with the first
     /// listening address, then cancels the server task.
@@ -410,7 +410,7 @@ struct TestHelpers {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension TestHelpers {
     static func makeTLSServerConfiguration(
         supportedHTTPVersions: Set<NIOHTTPServerConfiguration.HTTPVersion> = [.http1_1, .http2],
@@ -540,7 +540,7 @@ extension TestHelpers {
     #endif  // HTTP3 && UnstableHTTPDatagrams
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension HTTPFields {
     /// Returns the body encoding header fields required for the given HTTP version.
     static func makeBodyEncodingHeaders(for httpVersion: NIOHTTPServer.HTTPVersion) -> HTTPFields {
@@ -559,7 +559,7 @@ extension HTTPFields {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension String {
     static func makeScheme(for httpVersion: NIOHTTPServer.HTTPVersion) -> String {
         switch httpVersion {
@@ -577,7 +577,7 @@ extension String {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension HTTPRequest {
     /// Creates an ``HTTPRequest`` with the appropriate headers for the given `httpVersion`.
     static func makeRequest(
@@ -596,7 +596,7 @@ extension HTTPRequest {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension HTTPResponse {
     /// Creates an ``HTTPResponse`` with the given status and the appropriate headers for the given `httpVersion`.
     static func makeResponse(
@@ -610,7 +610,7 @@ extension HTTPResponse {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension HTTPRequestPart {
     static func testHead(
         method: HTTPRequest.Method,
diff --git a/Tests/NIOHTTPServerTests/Utilities/NIOClient/NIOClient+HTTP1.swift b/Tests/NIOHTTPServerTests/Utilities/NIOClient/NIOClient+HTTP1.swift
index 756242e..14ea590 100644
--- a/Tests/NIOHTTPServerTests/Utilities/NIOClient/NIOClient+HTTP1.swift
+++ b/Tests/NIOHTTPServerTests/Utilities/NIOClient/NIOClient+HTTP1.swift
@@ -19,7 +19,7 @@ import NIOHTTPTypes
 import NIOHTTPTypesHTTP1
 import NIOPosix
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension Channel {
     /// Adds HTTP/1.1 client handlers to the pipeline.
     func configureTestHTTP1ClientPipeline(
@@ -48,7 +48,7 @@ extension Channel {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension ClientBootstrap {
     /// Connects to the provided `serverAddress` over plaintext HTTP/1.1 and returns a ``TestClientConnection``
     /// wrapping the established connection. Use ``TestClientConnection/makeRequestChannel()`` to obtain a
diff --git a/Tests/NIOHTTPServerTests/Utilities/NIOClient/NIOClient+HTTP3.swift b/Tests/NIOHTTPServerTests/Utilities/NIOClient/NIOClient+HTTP3.swift
index f0748cc..38fbbcb 100644
--- a/Tests/NIOHTTPServerTests/Utilities/NIOClient/NIOClient+HTTP3.swift
+++ b/Tests/NIOHTTPServerTests/Utilities/NIOClient/NIOClient+HTTP3.swift
@@ -24,7 +24,7 @@ import NIOHTTPTypesHTTP1
 import NIOPosix
 import NIOQUIC
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct TestHTTP3SingleConnectionCreator: HTTP3ConnectionCreator {
     let quicHandler: QUICHandler<QUICStreamChannels>
     let connectionInitializer: @Sendable (any Channel, NIOQUIC.QUICStreamCreator) -> EventLoopFuture<any Channel>
@@ -62,7 +62,7 @@ struct TestHTTP3SingleConnectionCreator: HTTP3ConnectionCreator {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension Channel {
     func makeConnectionCreator(
         logger: Logger,
@@ -112,7 +112,7 @@ extension Channel {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension DatagramBootstrap {
     /// Sets up a test HTTP/3 client and returns the QUIC connection channel and the connection multiplexer.
     func setupTestHTTP3Client(
@@ -144,7 +144,7 @@ extension DatagramBootstrap {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension HTTP3ClientConnection {
     /// Opens a single request stream on this connection wrapped in a `NIOAsyncChannel`. The stream is closed by the
     /// caller using `executeThenClose`.
diff --git a/Tests/NIOHTTPServerTests/Utilities/NIOClient/NIOClient+SecureUpgrade.swift b/Tests/NIOHTTPServerTests/Utilities/NIOClient/NIOClient+SecureUpgrade.swift
index 8c30e1b..6b188c6 100644
--- a/Tests/NIOHTTPServerTests/Utilities/NIOClient/NIOClient+SecureUpgrade.swift
+++ b/Tests/NIOHTTPServerTests/Utilities/NIOClient/NIOClient+SecureUpgrade.swift
@@ -20,7 +20,7 @@ import NIOSSL
 
 @testable import NIOHTTPServer
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 /// Provides a HTTP client with ALPN negotiation.
 extension Channel {
     /// Adds a ``NIOSSLClientHandler`` configured with the provided `TLSConfiguration` to the pipeline.
@@ -52,7 +52,7 @@ extension Channel {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension ClientBootstrap {
     /// Connects the client to the specified address using the provided TLS configuration.
     func connectToTestSecureUpgradeHTTPServer(
diff --git a/Tests/NIOHTTPServerTests/Utilities/TestClientConnection.swift b/Tests/NIOHTTPServerTests/Utilities/TestClientConnection.swift
index 2b916e2..11433b5 100644
--- a/Tests/NIOHTTPServerTests/Utilities/TestClientConnection.swift
+++ b/Tests/NIOHTTPServerTests/Utilities/TestClientConnection.swift
@@ -33,7 +33,7 @@ import NIOQUICHelpers
 
 /// A testing utility that wraps an established HTTP/1.1, HTTP/2, or HTTP/3 client connection and provides an opaque
 /// interface for creating request streams.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct TestClientConnection {
     enum ConnectionProtocol {
         case http1(connectionChannel: NIOAsyncChannel<HTTPResponsePart, HTTPRequestPart>)
@@ -156,7 +156,7 @@ struct TestClientConnection {
     #endif
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension TestClientConnection {
     init(
         alpnNegotiationResult: NIONegotiatedHTTPVersion<
@@ -180,7 +180,7 @@ extension TestClientConnection {
     }
 }
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension TestClientConnection {
     /// The information needed to establish a test client connection to a ``NIOHTTPServer``.
     struct Configuration {
diff --git a/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/NIOHTTPServer+HTTP1.swift b/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/NIOHTTPServer+HTTP1.swift
index b87e15c..8253e44 100644
--- a/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/NIOHTTPServer+HTTP1.swift
+++ b/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/NIOHTTPServer+HTTP1.swift
@@ -18,7 +18,7 @@ import NIOHTTPTypes
 
 @testable import NIOHTTPServer
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     /// Starts serving plaintext HTTP/1.1 using the provided testing channel instead of using `ServerBootstrap` as
     /// `NIOHTTPServer` normally does.
diff --git a/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/NIOHTTPServer+SecureUpgrade.swift b/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/NIOHTTPServer+SecureUpgrade.swift
index e339b82..39df128 100644
--- a/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/NIOHTTPServer+SecureUpgrade.swift
+++ b/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/NIOHTTPServer+SecureUpgrade.swift
@@ -18,7 +18,7 @@ import NIOHTTPTypes
 
 @testable import NIOHTTPServer
 
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 extension NIOHTTPServer {
     /// Starts serving with the Secure Upgrade transport using the provided testing channel instead of using
     /// `ServerBootstrap` as `NIOHTTPServer` normally does.
diff --git a/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/TestingChannelServer+HTTP1.swift b/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/TestingChannelServer+HTTP1.swift
index ab0caf3..3b30092 100644
--- a/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/TestingChannelServer+HTTP1.swift
+++ b/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/TestingChannelServer+HTTP1.swift
@@ -31,7 +31,7 @@ import NIOHTTPTypes
 /// This provider vends a HTTP client channel (also backed by a `NIOAsyncTestingChannel`) that can be used to send
 /// requests and observe responses in terms of HTTP types (`HTTPRequestPart` and `HTTPResponsePart`) to the server
 /// connection channel.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct TestingChannelHTTP1Server {
     let server: NIOHTTPServer
     let serverTestChannel: NIOAsyncTestingChannel
diff --git a/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/TestingChannelServer+SecureUpgrade.swift b/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/TestingChannelServer+SecureUpgrade.swift
index 28c0a3a..35dfeb0 100644
--- a/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/TestingChannelServer+SecureUpgrade.swift
+++ b/Tests/NIOHTTPServerTests/Utilities/TestingChannelClientServer/TestingChannelServer+SecureUpgrade.swift
@@ -23,7 +23,7 @@ import X509
 @testable import NIOHTTPServer
 
 /// Like ``TestingChannelHTTP1Server``, but for Secure Upgrade.
-@available(anyAppleOS 26.0, *)
+@available(anyAppleOS 27.0, *)
 struct TestingChannelSecureUpgradeServer {
     let server: NIOHTTPServer
     let serverTestChannel: NIOAsyncTestingChannel