diff --git a/public_html/includes/class/class.LSformElement.php b/public_html/includes/class/class.LSformElement.php
index ad17ff07..64c7c1ad 100644
--- a/public_html/includes/class/class.LSformElement.php
+++ b/public_html/includes/class/class.LSformElement.php
@@ -252,7 +252,7 @@ class LSformElement {
    * @retval boolean True si le champ est à valeur multiple, False sinon
    */
   function isMultiple() {
-    return ($this -> params['multiple'] == true);
+    return ( (isset($this -> params['multiple']))?($this -> params['multiple'] == true):false );
   }
   
  /**