diff --git a/ext/json/tests/003.phpt b/ext/json/tests/003.phpt
index 6ae92bbebd1..f10baa9d12a 100644
--- a/ext/json/tests/003.phpt
+++ b/ext/json/tests/003.phpt
@@ -11,6 +11,9 @@ $a[] = &$a;
 var_dump($a);
 var_dump(json_encode($a));
 
+/* Break circular data structure to prevent memory leaks */
+unset($a[0]);
+
 echo "Done\n";
 ?>
 --EXPECTF--