diff --git a/pkg/mutation_observer/test/mutation_observer_test.dart b/pkg/mutation_observer/test/mutation_observer_test.dart
index e3bbdf4bbce..6f257e4fd35 100644
--- a/pkg/mutation_observer/test/mutation_observer_test.dart
+++ b/pkg/mutation_observer/test/mutation_observer_test.dart
@@ -55,7 +55,7 @@ testMutationObserver() {
         }
       }
 
-      return expectAsyncUntil2(callback, () => done);
+      return expectAsyncUntil(callback, () => done);
     }
 
     test('empty options is syntax error', () {