diff --git a/app/models/at_message.rb b/app/models/at_message.rb
index 1a75c4aae..7b65edead 100644
--- a/app/models/at_message.rb
+++ b/app/models/at_message.rb
@@ -1,3 +1,5 @@
+#coding=utf-8
+
 class AtMessage < ActiveRecord::Base
   belongs_to :user
   belongs_to :sender, class_name: "User", foreign_key: "sender_id"