diff --git a/example/lib/main.dart b/example/lib/main.dart
index e0e4e653..af4384ce 100644
--- a/example/lib/main.dart
+++ b/example/lib/main.dart
@@ -97,7 +97,7 @@ class _MyHomePageState extends State<MyHomePage> {
   final flutterWebViewPlugin = FlutterWebviewPlugin();
 
   // On destroy stream
-  StreamSubscription _onDestroy;
+  StreamSubscription<void> _onDestroy;
 
   // On urlChanged stream
   StreamSubscription<String> _onUrlChanged;