diff --git a/Tests/Unit/Domain/Search/QueryFactoryTest.php b/Tests/Unit/Domain/Search/QueryFactoryTest.php
index 570d5f0..45b77a9 100644
--- a/Tests/Unit/Domain/Search/QueryFactoryTest.php
+++ b/Tests/Unit/Domain/Search/QueryFactoryTest.php
@@ -397,7 +397,7 @@ class QueryFactoryTest extends AbstractUnitTestCase
 
         $query = $this->subject->create($searchRequest);
         $this->assertInstanceOf(
-            stdClass,
+            'stdClass',
             $query->toArray()['query']['match_all'],
             'Empty search request does not create expected query.'
         );