diff --git a/packages/firebase_ui_auth/doc/README.md b/packages/firebase_ui_auth/doc/README.md
index a3d85b0f71de..ff8628be8566 100644
--- a/packages/firebase_ui_auth/doc/README.md
+++ b/packages/firebase_ui_auth/doc/README.md
@@ -33,7 +33,7 @@ flutterfire configure
 Initialize firebase app:
 
 ```dart
-void main() {
+Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
 
   await Firebase.initializeApp(options: DefaultFirebaseOptions.currentPlatform);