diff --git a/.github/workflows/on-pull-request.yaml b/.github/workflows/on-pull-request.yaml
index e3519a1..f84a447 100644
--- a/.github/workflows/on-pull-request.yaml
+++ b/.github/workflows/on-pull-request.yaml
@@ -13,12 +13,7 @@ on:
 jobs:
   on-pull-request:
     name: test
-    strategy:
-      matrix:
-        go-version:
-          - 1.24.x
-        os: [ ubuntu-latest ]
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-latest
     steps:
       - name: Checkout
         uses: actions/checkout@v5
@@ -26,7 +21,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v6
         with:
-          go-version: ${{ matrix.go-version }}
+          go-version-file: go.mod
           cache: true # caching and restoring go modules and build outputs
 
       - run: go env
@@ -45,7 +40,7 @@ jobs:
       - name: golangci-lint
         uses: golangci/golangci-lint-action@v8
         with:
-          version: v2.6.1
+          version: v2.15.0
           skip-cache: true  # cache/restore is done by actions/setup-go@v3 step
           args: -v
 
diff --git a/Makefile b/Makefile
index a57b60d..458d732 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 GOLANGCI_LINT = $(GOPATH)/bin/golangci-lint
-GOLANGCI_LINT_VERSION = v1.61.0
+GOLANGCI_LINT_VERSION = v2.15.0
 
 $(GOLANGCI_LINT): ## Download Go linter
 	curl -sfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(GOPATH)/bin $(GOLANGCI_LINT_VERSION)
diff --git a/go.mod b/go.mod
index 7f95eba..5eeb2a5 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/groupcache/groupcache-go/v3
 
-go 1.24.0
+go 1.26.10
 
 require (
 	github.com/kapetan-io/tackle v0.13.0
diff --git a/transport/mock_transport.go b/transport/mock_transport.go
index f72ecc9..da34b33 100644
--- a/transport/mock_transport.go
+++ b/transport/mock_transport.go
@@ -182,7 +182,7 @@ func (s *peerStats) Report() string {
 	// Map keys have no guaranteed order, so we sort the keys here.
 	slices.Sort(sorted)
 	for i := 0; i < len(sorted); i++ {
-		b.WriteString(fmt.Sprintf("%s = %d ", sorted[i], s.stats[sorted[i]]))
+		fmt.Fprintf(&b, "%s = %d ", sorted[i], s.stats[sorted[i]])
 	}
 	return strings.TrimSpace(b.String())
 }