diff --git a/htdocs/don/class/don.class.php b/htdocs/don/class/don.class.php
index 5e035febd14..b6604133c31 100644
--- a/htdocs/don/class/don.class.php
+++ b/htdocs/don/class/don.class.php
@@ -653,7 +653,7 @@ class Don extends CommonObject
         }
         else if (! empty($ref))
         {
-        	$sql.= " AND ref='".$this->db->escape($ref)."'";
+        	$sql.= " AND d.ref='".$this->db->escape($ref)."'";
         }
 
         dol_syslog(get_class($this)."::fetch", LOG_DEBUG);