diff --git a/htdocs/comm/propal/class/propal.class.php b/htdocs/comm/propal/class/propal.class.php
index 7890f9036b424478383a5b6d26e8ca2e69c44e1a..b7f55bd80b722b56543b1711a3a934a6b144d35e 100644
--- a/htdocs/comm/propal/class/propal.class.php
+++ b/htdocs/comm/propal/class/propal.class.php
@@ -964,7 +964,7 @@ class Propal extends CommonObject
         $this->date			= $now;
         $this->datep		= $now;    // deprecated
         $this->fin_validite	= $this->date + ($this->duree_validite * 24 * 3600);
-        if (empty(MAIN_KEEP_REF_CUSTOMER_ON_CLONING)) $this->ref_client	= '';
+        if (empty($conf->global->MAIN_KEEP_REF_CUSTOMER_ON_CLONING)) $this->ref_client	= '';
 
         // Set ref
         require_once DOL_DOCUMENT_ROOT ."/core/modules/propale/".$conf->global->PROPALE_ADDON.'.php';