diff --git a/shadowsocks/asyncdns.py b/shadowsocks/asyncdns.py
index 009c2d3..b639dec 100644
--- a/shadowsocks/asyncdns.py
+++ b/shadowsocks/asyncdns.py
@@ -27,14 +27,13 @@ import socket
 import struct
 import re
 import logging
-import common
-import lru_cache
-import eventloop
+
+from shadowsocks import common, lru_cache, eventloop
 
 
 CACHE_SWEEP_INTERVAL = 30
 
-VALID_HOSTNAME = re.compile("(?!-)[A-Z\d-]{1,63}(?<!-)$", re.IGNORECASE)
+VALID_HOSTNAME = re.compile(r"(?!-)[A-Z\d-]{1,63}(?<!-)$", re.IGNORECASE)
 
 common.patch_socket()
 
diff --git a/shadowsocks/encrypt.py b/shadowsocks/encrypt.py
index 2e66175..45059de 100644
--- a/shadowsocks/encrypt.py
+++ b/shadowsocks/encrypt.py
@@ -26,19 +26,17 @@ import hashlib
 import string
 import struct
 import logging
-import crypto.m2
-import crypto.rc4_md5
-import crypto.salsa20_ctr
-import crypto.ctypes_openssl
+
+from shadowsocks.crypto import m2, rc4_md5, salsa20_ctr, ctypes_openssl
 
 
 method_supported = {}
 
-method_supported.update(crypto.rc4_md5.ciphers)
-method_supported.update(crypto.salsa20_ctr.ciphers)
-method_supported.update(crypto.ctypes_openssl.ciphers)
+method_supported.update(rc4_md5.ciphers)
+method_supported.update(salsa20_ctr.ciphers)
+method_supported.update(ctypes_openssl.ciphers)
 # let M2Crypto override ctypes_openssl
-method_supported.update(crypto.m2.ciphers)
+method_supported.update(m2.ciphers)
 
 
 def random_string(length):
diff --git a/shadowsocks/local.py b/shadowsocks/local.py
index be4d66f..24e7ad7 100755
--- a/shadowsocks/local.py
+++ b/shadowsocks/local.py
@@ -25,12 +25,8 @@ import sys
 import os
 import logging
 import signal
-import utils
-import encrypt
-import eventloop
-import tcprelay
-import udprelay
-import asyncdns
+
+from shadowsocks import utils, encrypt, eventloop, tcprelay, udprelay, asyncdns
 
 
 def main():
diff --git a/shadowsocks/server.py b/shadowsocks/server.py
index fd38dd9..2741ac1 100755
--- a/shadowsocks/server.py
+++ b/shadowsocks/server.py
@@ -25,12 +25,8 @@ import sys
 import os
 import logging
 import signal
-import utils
-import encrypt
-import eventloop
-import tcprelay
-import udprelay
-import asyncdns
+
+from shadowsocks import utils, encrypt, eventloop, tcprelay, udprelay, asyncdns
 
 
 def main():
diff --git a/shadowsocks/tcprelay.py b/shadowsocks/tcprelay.py
index 372f1e2..ec6adbe 100644
--- a/shadowsocks/tcprelay.py
+++ b/shadowsocks/tcprelay.py
@@ -28,10 +28,9 @@ import struct
 import logging
 import traceback
 import random
-import encrypt
-import eventloop
-import utils
-from common import parse_header
+
+from shadowsocks import encrypt, eventloop, utils
+from shadowsocks.common import parse_header
 
 
 TIMEOUTS_CLEAN_SIZE = 512
diff --git a/shadowsocks/udprelay.py b/shadowsocks/udprelay.py
index 64d6a43..bfd688a 100644
--- a/shadowsocks/udprelay.py
+++ b/shadowsocks/udprelay.py
@@ -72,10 +72,9 @@ import logging
 import struct
 import errno
 import random
-import encrypt
-import eventloop
-import lru_cache
-from common import parse_header, pack_addr
+
+from shadowsocks import encrypt, eventloop, lru_cache
+from shadowsocks.common import parse_header, pack_addr
 
 
 BUF_SIZE = 65536