diff --git a/library/includes/init_bb.php b/library/includes/init_bb.php
index 0efe1e87e..96d6c906d 100644
--- a/library/includes/init_bb.php
+++ b/library/includes/init_bb.php
@@ -433,7 +433,7 @@ if (
  * Exit if board is disabled via trigger
  */
 if (($bb_cfg['board_disable'] || file_exists(BB_DISABLED)) && !defined('IN_ADMIN') && !defined('IN_AJAX') && !defined('IN_LOGIN')) {
-    header('HTTP/1.0 503 Service Unavailable');
+    http_response_code(503);
     if ($bb_cfg['board_disable']) {
         // admin lock
         send_no_cache_headers();