diff --git a/tests/test_framework/phpbb_functional_test_case.php b/tests/test_framework/phpbb_functional_test_case.php
index 57cc0f8959..a1c642bf38 100644
--- a/tests/test_framework/phpbb_functional_test_case.php
+++ b/tests/test_framework/phpbb_functional_test_case.php
@@ -24,7 +24,7 @@ class phpbb_functional_test_case extends phpbb_test_case
 			self::markTestSkipped('phar extension is not loaded');
 		}
 
-		require_once __DIR__ . '/../../vendor/goutte.phar';
+		require_once 'phar://' . __DIR__ . '/../../vendor/goutte.phar';
 	}
 
 	public function setUp()