diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 94e5d27b..f9b2c9b4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        go: ['1.25', '1.26']
+        go: ['1.26', '1.27']
 
     steps:
     - name: Check out code
diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
index 4b8781ae..caf95200 100644
--- a/.github/workflows/nightly.yml
+++ b/.github/workflows/nightly.yml
@@ -36,7 +36,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@b7ad1dad31e06c5925ef5d2fc7ad053ef454303e # v7.0.0
       with:
-        go-version: '1.25'
+        go-version: '1.26'
 
     - name: Install golint
       run: go install golang.org/x/lint/golint@latest
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 316157b7..0adaa5a9 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -51,7 +51,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@b7ad1dad31e06c5925ef5d2fc7ad053ef454303e # v7.0.0
       with:
-        go-version: '1.25'
+        go-version: '1.26'
 
     - name: Install golint
       run: go install golang.org/x/lint/golint@latest
diff --git a/README.md b/README.md
index 61441c47..294d1bf2 100644
--- a/README.md
+++ b/README.md
@@ -46,11 +46,11 @@ requests, code review feedback, and also pull requests.
 
 The Firebase Admin Go SDK is compatible with the two most-recent major Go releases, following the same [policy](https://go.dev/doc/devel/release#policy) as the Go programming language. This means the currently supported versions are:
 
-- Go 1.25
 - Go 1.26
+- Go 1.27
 
 [Continuous integration](https://github.com/firebase/firebase-admin-go/actions) system
-tests the code on Go 1.25 and 1.26.
+tests the code on Go 1.26 and 1.27.
 
 ## Documentation
 
diff --git a/auth/auth_test.go b/auth/auth_test.go
index 53daf79f..77090d55 100644
--- a/auth/auth_test.go
+++ b/auth/auth_test.go
@@ -525,7 +525,7 @@ func TestVerifyIDTokenClockSkew(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			ft, err := client.VerifyIDToken(context.Background(), tc.token)
 			if err != nil {
-				t.Fatalf("VerifyIDToken(%q) = (%q, %v); want = (token, nil)", tc.name, ft, err)
+				t.Fatalf("VerifyIDToken(%q) = (%v, %v); want = (token, nil)", tc.name, ft, err)
 			}
 			if ft.Claims["admin"] != true {
 				t.Errorf("Claims['admin'] = %v; want = true", ft.Claims["admin"])
diff --git a/db/query_test.go b/db/query_test.go
index df05bf1c..a3878b56 100644
--- a/db/query_test.go
+++ b/db/query_test.go
@@ -752,7 +752,7 @@ func TestGetOrderedWithLeafNode(t *testing.T) {
 		t.Fatalf("GetOrdered(chid) = %d; want = 1", len(result))
 	}
 	if result[0].Key() != "0" {
-		t.Errorf("GetOrdered(value).Key() = %v; want = %q", result[0].Key(), 0)
+		t.Errorf("GetOrdered(value).Key() = %v; want = %q", result[0].Key(), "0")
 	}
 
 	var v interface{}
diff --git a/go.mod b/go.mod
index 82678e9f..586152a1 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module firebase.google.com/go/v4
 
-go 1.25.0
+go 1.26.0
 
 require (
 	cloud.google.com/go/firestore v1.22.0