diff --git a/core/event.class.inc.php b/core/event.class.inc.php
index 2c1e4ccf8..66d904418 100644
--- a/core/event.class.inc.php
+++ b/core/event.class.inc.php
@@ -351,7 +351,7 @@ class EventLoginUsage extends Event
 		MetaModel::Init_Params($aParams);
 		MetaModel::Init_InheritAttributes();
 
-		MetaModel::Init_AddAttribute(new AttributeExternalKey("user_id", array("targetclass"=>"User", "jointype"=> "", "allowed_values"=>null, "sql"=>"user_id", "is_null_allowed"=>false, "on_target_delete"=>DEL_MANUAL, "depends_on"=>array())));
+		MetaModel::Init_AddAttribute(new AttributeExternalKey("user_id", array("targetclass"=>"User", "jointype"=> "", "allowed_values"=>null, "sql"=>"user_id", "is_null_allowed"=>false, "on_target_delete"=>DEL_SILENT, "depends_on"=>array())));
 		$aZList = array('date', 'user_id');
 		if (MetaModel::IsValidAttCode('Contact', 'name'))
 		{