diff --git a/tests/ParentClassResolver/Fixture/SomeClassWithInternalParent.php b/tests/ParentClassResolver/Fixture/SomeClassWithInternalParent.php
new file mode 100644
index 0000000..647b9b6
--- /dev/null
+++ b/tests/ParentClassResolver/Fixture/SomeClassWithInternalParent.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TomasVotruba\Finalize\Tests\ParentClassResolver\Fixture;
+
+final class SomeClassWithInternalParent extends \ArrayObject
+{
+}