diff --git a/htdocs/main.inc.php b/htdocs/main.inc.php
index e0055890152..370e7ac1278 100644
--- a/htdocs/main.inc.php
+++ b/htdocs/main.inc.php
@@ -386,7 +386,7 @@ if (!defined('NOLOGIN') && !defined('NOIPCHECK') && !empty($dolibarr_main_restri
 
 // Loading of additional presentation includes
 if (!defined('NOREQUIREHTML')) require_once DOL_DOCUMENT_ROOT.'/core/class/html.form.class.php'; // Need 660ko memory (800ko in 2.2)
-require_once DOL_DOCUMENT_ROOT.'/core/lib/ajax.lib.php'; // Need 22ko memory
+if (!defined('NOREQUIREAJAX')) require_once DOL_DOCUMENT_ROOT.'/core/lib/ajax.lib.php'; // Need 22ko memory
 
 // If install or upgrade process not done or not completely finished, we call the install page.
 if (!empty($conf->global->MAIN_NOT_INSTALLED) || !empty($conf->global->MAIN_NOT_UPGRADED))