diff --git a/shadowsocks/asyncdns.py b/shadowsocks/asyncdns.py
index e60a383..ea705b2 100644
--- a/shadowsocks/asyncdns.py
+++ b/shadowsocks/asyncdns.py
@@ -18,7 +18,6 @@
 from __future__ import absolute_import, division, print_function, \
     with_statement
 
-import time
 import os
 import socket
 import struct
diff --git a/shadowsocks/udprelay.py b/shadowsocks/udprelay.py
index 7e5e2c3..b67770a 100644
--- a/shadowsocks/udprelay.py
+++ b/shadowsocks/udprelay.py
@@ -62,7 +62,6 @@
 from __future__ import absolute_import, division, print_function, \
     with_statement
 
-import time
 import socket
 import logging
 import struct
diff --git a/tests/gen_multiple_passwd.py b/tests/gen_multiple_passwd.py
index a058582..62586c2 100644
--- a/tests/gen_multiple_passwd.py
+++ b/tests/gen_multiple_passwd.py
@@ -1,6 +1,5 @@
 #!/usr/bin/python
 
-import os
 import json
 
 with open('server-multi-passwd-performance.json', 'wb') as f: