diff --git a/htdocs/core/class/commonobject.class.php b/htdocs/core/class/commonobject.class.php
index 3287ac5d4b7ab147acc777281d0bbbadf3ff7a2d..c26251f231253741fb81f22a0307ca2a58faa381 100644
--- a/htdocs/core/class/commonobject.class.php
+++ b/htdocs/core/class/commonobject.class.php
@@ -744,7 +744,8 @@ abstract class CommonObject
 
         $sql = "DELETE FROM ".MAIN_DB_PREFIX."element_contact";
         $sql.= " WHERE element_id = ".$this->id;
-        $sql.= " AND fk_c_type_contact IN (".$listId.")";
+        if ($listId)
+        	$sql.= " AND fk_c_type_contact IN (".$listId.")";
 
         dol_syslog(get_class($this)."::delete_linked_contact", LOG_DEBUG);
         if ($this->db->query($sql))