diff --git a/FirebaseAuth/CHANGELOG.md b/FirebaseAuth/CHANGELOG.md
index 3b47ccbe470..b6bbd004d35 100644
--- a/FirebaseAuth/CHANGELOG.md
+++ b/FirebaseAuth/CHANGELOG.md
@@ -1,6 +1,8 @@
 # 12.19.0
 - [fixed] Fixed a build error in app extensions introduced in 12.18.0, where
   `AuthNotificationManager` referenced `UIApplication.shared` directly. (#16583)
+- [fixed] Fixed a build error in Objective-C app extensions by using internal
+  imports for internal framework dependencies. (#16590)
 - [fixed] Fixed a persistent crash when interacting with App Check under some
   Swift toolchains (like the Flutter SDK) by avoiding a compiler bug in Swift
   concurrency thunk generation. (#16549)
diff --git a/FirebaseAuth/Sources/Swift/ActionCode/ActionCodeSettings.swift b/FirebaseAuth/Sources/Swift/ActionCode/ActionCodeSettings.swift
index 74472e33c71..f5c0b6f00f0 100644
--- a/FirebaseAuth/Sources/Swift/ActionCode/ActionCodeSettings.swift
+++ b/FirebaseAuth/Sources/Swift/ActionCode/ActionCodeSettings.swift
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import FirebaseCoreInternal
+internal import FirebaseCoreInternal
 import Foundation
 
 // TODO(Swift 6 Breaking): Consider breaking up into a checked Sendable Swift
diff --git a/FirebaseAuth/Sources/Swift/Auth/Auth.swift b/FirebaseAuth/Sources/Swift/Auth/Auth.swift
index fa1bde8eebc..cfac20f42a5 100644
--- a/FirebaseAuth/Sources/Swift/Auth/Auth.swift
+++ b/FirebaseAuth/Sources/Swift/Auth/Auth.swift
@@ -17,7 +17,7 @@ import Foundation
 import FirebaseAppCheckInterop
 import FirebaseAuthInterop
 import FirebaseCore
-import FirebaseCoreExtension
+internal import FirebaseCoreExtension
 #if COCOAPODS
   internal import GoogleUtilities
 #else
diff --git a/FirebaseAuth/Sources/Swift/Auth/AuthComponent.swift b/FirebaseAuth/Sources/Swift/Auth/AuthComponent.swift
index daef3287670..6f81f0e1acd 100644
--- a/FirebaseAuth/Sources/Swift/Auth/AuthComponent.swift
+++ b/FirebaseAuth/Sources/Swift/Auth/AuthComponent.swift
@@ -17,7 +17,7 @@ import Foundation
 import FirebaseAppCheckInterop
 import FirebaseAuthInterop
 import FirebaseCore
-import FirebaseCoreExtension
+internal import FirebaseCoreExtension
 
 @objc(FIRAuthComponent)
 class AuthComponent: NSObject, Library, ComponentLifecycleMaintainer {
diff --git a/FirebaseAuth/Sources/Swift/Backend/AuthBackend.swift b/FirebaseAuth/Sources/Swift/Backend/AuthBackend.swift
index 20d41086548..70c31de56c8 100644
--- a/FirebaseAuth/Sources/Swift/Backend/AuthBackend.swift
+++ b/FirebaseAuth/Sources/Swift/Backend/AuthBackend.swift
@@ -13,7 +13,7 @@
 // limitations under the License.
 
 import FirebaseCore
-import FirebaseCoreExtension
+internal import FirebaseCoreExtension
 import Foundation
 #if COCOAPODS
   import GTMSessionFetcher
diff --git a/FirebaseAuth/Sources/Swift/Backend/AuthBackendRPCIssuer.swift b/FirebaseAuth/Sources/Swift/Backend/AuthBackendRPCIssuer.swift
index d52e63e1bbc..99bdcd292c6 100644
--- a/FirebaseAuth/Sources/Swift/Backend/AuthBackendRPCIssuer.swift
+++ b/FirebaseAuth/Sources/Swift/Backend/AuthBackendRPCIssuer.swift
@@ -13,7 +13,7 @@
 // limitations under the License.
 
 import FirebaseCore
-import FirebaseCoreExtension
+internal import FirebaseCoreExtension
 import Foundation
 #if COCOAPODS
   @preconcurrency import GTMSessionFetcher
diff --git a/FirebaseAuth/Sources/Swift/Backend/AuthRequestConfiguration.swift b/FirebaseAuth/Sources/Swift/Backend/AuthRequestConfiguration.swift
index 21cb7a2f3a9..979844400d9 100644
--- a/FirebaseAuth/Sources/Swift/Backend/AuthRequestConfiguration.swift
+++ b/FirebaseAuth/Sources/Swift/Backend/AuthRequestConfiguration.swift
@@ -15,7 +15,7 @@
 import Foundation
 
 import FirebaseAppCheckInterop
-import FirebaseCoreExtension
+internal import FirebaseCoreExtension
 
 /// Defines configurations to be added to a request to Firebase Auth's backend.
 final class AuthRequestConfiguration {
diff --git a/FirebaseAuth/Sources/Swift/Storage/AuthKeychainServices.swift b/FirebaseAuth/Sources/Swift/Storage/AuthKeychainServices.swift
index 2fe1dbda22d..457230856f9 100644
--- a/FirebaseAuth/Sources/Swift/Storage/AuthKeychainServices.swift
+++ b/FirebaseAuth/Sources/Swift/Storage/AuthKeychainServices.swift
@@ -12,8 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import FirebaseCoreExtension
-import FirebaseCoreInternal
+internal import FirebaseCoreExtension
+internal import FirebaseCoreInternal
 import Foundation
 
 /// The prefix string for keychain item account attribute before the key.
diff --git a/FirebaseAuth/Sources/Swift/SystemService/SecureTokenService.swift b/FirebaseAuth/Sources/Swift/SystemService/SecureTokenService.swift
index bc013b3ae17..4683df9fa8e 100644
--- a/FirebaseAuth/Sources/Swift/SystemService/SecureTokenService.swift
+++ b/FirebaseAuth/Sources/Swift/SystemService/SecureTokenService.swift
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import FirebaseCoreInternal
+internal import FirebaseCoreInternal
 import Foundation
 
 private let kFiveMinutes = 5 * 60.0
diff --git a/FirebaseAuth/Sources/Swift/Utilities/AuthLog.swift b/FirebaseAuth/Sources/Swift/Utilities/AuthLog.swift
index b3d8e940791..b2eb841d6ec 100644
--- a/FirebaseAuth/Sources/Swift/Utilities/AuthLog.swift
+++ b/FirebaseAuth/Sources/Swift/Utilities/AuthLog.swift
@@ -13,7 +13,7 @@
 // limitations under the License.
 
 import FirebaseCore
-import FirebaseCoreExtension
+internal import FirebaseCoreExtension
 import Foundation
 
 enum AuthLog {
diff --git a/FirebaseAuth/Sources/Swift/Utilities/AuthURLPresenter.swift b/FirebaseAuth/Sources/Swift/Utilities/AuthURLPresenter.swift
index b6cd1a4fa84..c5f2115dca0 100644
--- a/FirebaseAuth/Sources/Swift/Utilities/AuthURLPresenter.swift
+++ b/FirebaseAuth/Sources/Swift/Utilities/AuthURLPresenter.swift
@@ -15,9 +15,9 @@
 #if os(iOS)
 
   import Foundation
-  import SafariServices
+  internal import SafariServices
   import UIKit
-  import WebKit
+  internal import WebKit
 
   /// A Class responsible for presenting URL via SFSafariViewController or WKWebView.
   class AuthURLPresenter: NSObject,
diff --git a/FirebaseAuth/Sources/Swift/Utilities/AuthWebViewController.swift b/FirebaseAuth/Sources/Swift/Utilities/AuthWebViewController.swift
index e629578f12f..267bdf0f377 100644
--- a/FirebaseAuth/Sources/Swift/Utilities/AuthWebViewController.swift
+++ b/FirebaseAuth/Sources/Swift/Utilities/AuthWebViewController.swift
@@ -16,7 +16,7 @@
 
   import Foundation
   import UIKit
-  import WebKit
+  internal import WebKit
 
   /// Defines a delegate for AuthWebViewController
   protocol AuthWebViewControllerDelegate: AnyObject {