diff --git a/packages/google_sign_in/google_sign_in_android/CHANGELOG.md b/packages/google_sign_in/google_sign_in_android/CHANGELOG.md
index fd2d7d67db2..7e42f74fcc7 100644
--- a/packages/google_sign_in/google_sign_in_android/CHANGELOG.md
+++ b/packages/google_sign_in/google_sign_in_android/CHANGELOG.md
@@ -1,5 +1,6 @@
-## NEXT
+## 6.1.21
 
+* Updates `clearAuthCache` override to match base class declaration.
 * Updates minimum supported SDK version to Flutter 3.10/Dart 3.0.
 
 ## 6.1.20
diff --git a/packages/google_sign_in/google_sign_in_android/lib/google_sign_in_android.dart b/packages/google_sign_in/google_sign_in_android/lib/google_sign_in_android.dart
index 48f4abb75ca..fda32600fa9 100644
--- a/packages/google_sign_in/google_sign_in_android/lib/google_sign_in_android.dart
+++ b/packages/google_sign_in/google_sign_in_android/lib/google_sign_in_android.dart
@@ -86,10 +86,8 @@ class GoogleSignInAndroid extends GoogleSignInPlatform {
   }
 
   @override
-  Future<void> clearAuthCache({String? token}) {
-    // The token is not acutally nullable; see
-    // https://github.com/flutter/flutter/issues/129717
-    return _api.clearAuthCache(token!);
+  Future<void> clearAuthCache({required String token}) {
+    return _api.clearAuthCache(token);
   }
 
   @override
diff --git a/packages/google_sign_in/google_sign_in_android/pubspec.yaml b/packages/google_sign_in/google_sign_in_android/pubspec.yaml
index d121366de0a..91aebc1bf54 100644
--- a/packages/google_sign_in/google_sign_in_android/pubspec.yaml
+++ b/packages/google_sign_in/google_sign_in_android/pubspec.yaml
@@ -2,7 +2,7 @@ name: google_sign_in_android
 description: Android implementation of the google_sign_in plugin.
 repository: https://github.com/flutter/packages/tree/main/packages/google_sign_in/google_sign_in_android
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+google_sign_in%22
-version: 6.1.20
+version: 6.1.21
 
 environment:
   sdk: ">=3.0.0 <4.0.0"
diff --git a/packages/google_sign_in/google_sign_in_ios/CHANGELOG.md b/packages/google_sign_in/google_sign_in_ios/CHANGELOG.md
index 6724341e98d..05415d72976 100644
--- a/packages/google_sign_in/google_sign_in_ios/CHANGELOG.md
+++ b/packages/google_sign_in/google_sign_in_ios/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 5.7.2
+
+* Updates `clearAuthCache` override to match base class declaration.
+
 ## 5.7.1
 
 * Changes `pigeon` to a dev dependency.
diff --git a/packages/google_sign_in/google_sign_in_ios/lib/google_sign_in_ios.dart b/packages/google_sign_in/google_sign_in_ios/lib/google_sign_in_ios.dart
index 9c589501114..1ddaadfd759 100644
--- a/packages/google_sign_in/google_sign_in_ios/lib/google_sign_in_ios.dart
+++ b/packages/google_sign_in/google_sign_in_ios/lib/google_sign_in_ios.dart
@@ -86,7 +86,7 @@ class GoogleSignInIOS extends GoogleSignInPlatform {
   }
 
   @override
-  Future<void> clearAuthCache({String? token}) async {
+  Future<void> clearAuthCache({required String token}) async {
     // There's nothing to be done here on iOS since the expired/invalid
     // tokens are refreshed automatically by getTokens.
   }
diff --git a/packages/google_sign_in/google_sign_in_ios/pubspec.yaml b/packages/google_sign_in/google_sign_in_ios/pubspec.yaml
index d3a6316b651..579ac533d87 100644
--- a/packages/google_sign_in/google_sign_in_ios/pubspec.yaml
+++ b/packages/google_sign_in/google_sign_in_ios/pubspec.yaml
@@ -2,7 +2,7 @@ name: google_sign_in_ios
 description: iOS implementation of the google_sign_in plugin.
 repository: https://github.com/flutter/packages/tree/main/packages/google_sign_in/google_sign_in_ios
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+google_sign_in%22
-version: 5.7.1
+version: 5.7.2
 
 environment:
   sdk: ">=3.2.0 <4.0.0"