diff --git a/phpBB/includes/functions_convert.php b/phpBB/includes/functions_convert.php
index 058412429c..414f6f2f20 100644
--- a/phpBB/includes/functions_convert.php
+++ b/phpBB/includes/functions_convert.php
@@ -2089,7 +2089,7 @@ function fix_empty_primary_groups()
 */
 function remove_invalid_users()
 {
-	global $convert, $db;
+	global $convert, $db, $phpEx, $phpbb_root_path;
 
 	// username_clean is UNIQUE
 	$sql = 'SELECT user_id