diff --git a/tests/ext_test.php b/tests/ext_test.php
index 12dee45..492d64f 100644
--- a/tests/ext_test.php
+++ b/tests/ext_test.php
@@ -52,7 +52,7 @@ public function test_disable()
 
 	protected function create_extension_manager()
 	{
-		$phpbb_root_path = __DIR__ . './../../../../';
+		$phpbb_root_path = dirname(__DIR__, 2) . '/';
 		$php_ext = 'php';
 
 		$config = new \phpbb\config\config(['version' => PHPBB_VERSION]);