diff --git a/phpBB/install_new/startup.php b/phpBB/install_new/startup.php
index 766f6be38a..4d558d015f 100644
--- a/phpBB/install_new/startup.php
+++ b/phpBB/install_new/startup.php
@@ -62,6 +62,7 @@ $phpbb_adm_relative_path = (isset($phpbb_adm_relative_path)) ? $phpbb_adm_relati
 $phpbb_admin_path = (defined('PHPBB_ADMIN_PATH')) ? PHPBB_ADMIN_PATH : $phpbb_root_path . $phpbb_adm_relative_path;
 
 // Include files
+phpbb_require_updated('includes/constants.' . $phpEx, $phpbb_root_path);
 phpbb_require_updated('includes/functions.' . $phpEx, $phpbb_root_path);
 phpbb_require_updated('includes/functions_content.' . $phpEx, $phpbb_root_path);
 phpbb_include_updated('includes/functions_compatibility.' . $phpEx, $phpbb_root_path);