diff --git a/htdocs/core/class/commonobject.class.php b/htdocs/core/class/commonobject.class.php
index e0bab998982582d92245d2eef1469fc44541f642..03d044a2ee6d91a1334cfedd949046d03a9c5bbd 100644
--- a/htdocs/core/class/commonobject.class.php
+++ b/htdocs/core/class/commonobject.class.php
@@ -65,13 +65,15 @@ abstract class CommonObject
      */
     static function isExistingObject($element, $id, $ref='', $ref_ext='')
     {
-    	global $db;
+    	global $db,$conf;
 
 		$sql = "SELECT rowid, ref, ref_ext";
 		$sql.= " FROM ".MAIN_DB_PREFIX.$element;
-		if ($id > 0) $sql.= " WHERE rowid = ".$db->escape($id);
-		else if ($ref) $sql.= " WHERE ref = '".$db->escape($ref)."'";
-		else if ($ref_ext) $sql.= " WHERE ref_ext = '".$db->escape($ref_ext)."'";
+		$sql.= " WHERE entity IN (".getEntity($element).")" ; 
+		
+		if ($id > 0) $sql.= " AND rowid = ".$db->escape($id);
+		else if ($ref) $sql.= " AND ref = '".$db->escape($ref)."'";
+		else if ($ref_ext) $sql.= " AND ref_ext = '".$db->escape($ref_ext)."'";
 		else {
 			$error='ErrorWrongParameters';
 			dol_print_error(get_class()."::isExistingObject ".$error, LOG_ERR);