diff --git a/server.php b/server.php
index 70d5a11b..d3bf0192 100644
--- a/server.php
+++ b/server.php
@@ -92,6 +92,9 @@ function llxFooter() { }
 if (!$res && @file_exists("../../../main.inc.php")) $res = @include "../../../main.inc.php";
 if (!$res) die("Include of main fails");
 
+if(!defined('DOL_DOCUMENT_ROOT'))
+	define('DOL_DOCUMENT_ROOT', $dolibarr_main_document_root);
+
 require DOL_DOCUMENT_ROOT.'/core/lib/security2.lib.php';	// auth method
 require_once DOL_DOCUMENT_ROOT.'/contact/class/contact.class.php';