diff --git a/shadowsocks/obfsplugin/auth_chain.py b/shadowsocks/obfsplugin/auth_chain.py
index 91d75f9..b11d545 100644
--- a/shadowsocks/obfsplugin/auth_chain.py
+++ b/shadowsocks/obfsplugin/auth_chain.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+# -*- coding: utf-8 -*-
 #
 # Copyright 2015-2015 breakwa11
 #