diff --git a/angel_orm_generator/example/main.dart b/angel_orm_generator/example/main.dart
index 7651e8f9..2a19b3c8 100644
--- a/angel_orm_generator/example/main.dart
+++ b/angel_orm_generator/example/main.dart
@@ -33,7 +33,7 @@ class _FakeExecutor extends QueryExecutor {
   }
 
   @override
-  Future<T> transaction<T>(FutureOr<T> Function() f) {
+  Future<T> transaction<T>(FutureOr<T> Function(QueryExecutor) f) {
     throw new UnsupportedError('Transactions are not supported.');
   }
 }