diff --git a/test/classes/plugin/auth/PMA_AuthenticationCookie_test.php b/test/classes/plugin/auth/PMA_AuthenticationCookie_test.php
index b8fc54c808..81f6b08f29 100644
--- a/test/classes/plugin/auth/PMA_AuthenticationCookie_test.php
+++ b/test/classes/plugin/auth/PMA_AuthenticationCookie_test.php
@@ -17,6 +17,7 @@ require_once 'libraries/js_escape.lib.php';
 require_once 'libraries/sanitizing.lib.php';
 require_once 'libraries/database_interface.inc.php';
 require_once 'libraries/select_lang.lib.php';
+require_once 'libraries/plugins/auth/AuthenticationCookie.php';
 
 /**
  * tests for PMA\libraries\plugins\auth\AuthenticationCookie class