diff --git a/htdocs/core/class/commonobject.class.php b/htdocs/core/class/commonobject.class.php
index 2650c48b573..197f61735c3 100644
--- a/htdocs/core/class/commonobject.class.php
+++ b/htdocs/core/class/commonobject.class.php
@@ -6219,6 +6219,7 @@ abstract class CommonObject
 					return 'Error bad setup of extrafield';
 				}
 			}
+			else $value='';
 		}
 		elseif ($type == 'text' || $type == 'html')
 		{