diff --git a/tests/mock/cache.php b/tests/mock/cache.php
index b64c92ea89..bc18ca066b 100644
--- a/tests/mock/cache.php
+++ b/tests/mock/cache.php
@@ -123,6 +123,7 @@ class phpbb_mock_cache implements phpbb_cache_driver_interface
 	}
 	public function sql_save($query, $query_result, $ttl)
 	{
+		return $query_result;
 	}
 	public function sql_exists($query_id)
 	{