diff --git a/tests/e2e/Adapter/Base.php b/tests/e2e/Adapter/Base.php
index ef5820c61..4b9ebd1d2 100644
--- a/tests/e2e/Adapter/Base.php
+++ b/tests/e2e/Adapter/Base.php
@@ -5829,7 +5829,7 @@ public function testUpdateAttributeRename(): void
         }
     }
 
-    public function createRandomString($length = 10): string
+    public function createRandomString(int $length = 10): string
     {
         $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
         $charactersLength = strlen($characters);