diff --git a/htdocs/lib/functions.lib.php b/htdocs/lib/functions.lib.php
index 874af35b049..54fd231d7bd 100644
--- a/htdocs/lib/functions.lib.php
+++ b/htdocs/lib/functions.lib.php
@@ -33,9 +33,9 @@
  */
 
 // For compatibility during upgrade
-if (! defined('DOL_DOCUMENT_ROOT'))	 define('DOL_DOCUMENT_ROOT', '..');
-if (! defined('DOL_DOCUMENT_ROOT_ALT'))	 define('DOL_DOCUMENT_ROOT_ALT', '../custom');
-if (! defined('ADODB_DATE_VERSION')) include_once(DOL_DOCUMENT_ROOT."/includes/adodbtime/adodb-time.inc.php");
+if (! defined('DOL_DOCUMENT_ROOT'))	    define('DOL_DOCUMENT_ROOT', '..');
+if (! defined('DOL_DOCUMENT_ROOT_ALT'))	define('DOL_DOCUMENT_ROOT_ALT', '');	// If option not enabled, we keep it disabled but avoid warning
+if (! defined('ADODB_DATE_VERSION'))    include_once(DOL_DOCUMENT_ROOT."/includes/adodbtime/adodb-time.inc.php");
 
 
 /**