diff --git a/phpBB/includes/functions.php b/phpBB/includes/functions.php
index 8ca15a4908..3c26337f91 100644
--- a/phpBB/includes/functions.php
+++ b/phpBB/includes/functions.php
@@ -2231,6 +2231,7 @@ function phpbb_on_page($template, $user, $base_url, $num_items, $per_page, $star
 function append_sid($url, $params = false, $is_amp = true, $session_id = false)
 {
 	global $_SID, $_EXTRA_URL, $phpbb_hook;
+	global $phpbb_dispatcher;
 
 	if ($params === '' || (is_array($params) && empty($params)))
 	{