diff --git a/test/efficiency_bechmark_test.dart b/test/efficiency_bechmark_test.dart
index 8c268aa..38357e3 100644
--- a/test/efficiency_bechmark_test.dart
+++ b/test/efficiency_bechmark_test.dart
@@ -30,14 +30,14 @@ void main() {
     await tester.pumpAndSettle();
 
     // toggle sign in button two times
-    final switchButton = find.byKey(Key('user_switch'));
+    final switchButton = find.byKey(const Key('user_switch'));
     await tester.tap(switchButton);
     await tester.pumpAndSettle();
     await tester.tap(switchButton);
     await tester.pumpAndSettle();
 
     // go to cart
-    final cartButton = find.byKey(Key('cart_button'));
+    final cartButton = find.byKey(const Key('cart_button'));
     await tester.tap(cartButton);
     await tester.pumpAndSettle();
     final header = find.text('Warenkorb');