diff --git a/.travis.yml b/.travis.yml
index 4a11a47..5a885cc 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,26 +11,27 @@ cache:
 before_install:
   - sudo apt-get update -qq
   - sudo apt-get install -qq build-essential libssl-dev swig python-m2crypto python-numpy dnsutils
-  - pip install m2crypto salsa20 pep8 pyflakes nose
+  - pip install m2crypto salsa20 pep8 pyflakes nose coverage
   - sudo tests/socksify/install.sh
   - sudo tests/libsodium/install.sh
 script:
   - pep8 .
   - pyflakes .
-  - python tests/nose_plugin.py -v
+  - coverage run tests/nose_plugin.py -v
   - python setup.py sdist
-  - python tests/test.py -c tests/aes.json
-  - python tests/test.py -c tests/aes-ctr.json
-  - python tests/test.py -c tests/aes-cfb1.json
-  - python tests/test.py -c tests/aes-cfb8.json
-  - python tests/test.py -c tests/rc4-md5.json
-  - python tests/test.py -c tests/salsa20.json
-  - python tests/test.py -c tests/chacha20.json
-  - python tests/test.py -c tests/salsa20-ctr.json
-  - python tests/test.py -c tests/table.json
-  - python tests/test.py -c tests/server-multi-ports.json
-  - python tests/test.py -s tests/server-multi-passwd.json -c tests/server-multi-passwd-client-side.json
-  - python tests/test.py -c tests/workers.json
-  - python tests/test.py -s tests/ipv6.json -c tests/ipv6-client-side.json
-  - python tests/test.py -b "-m rc4-md5 -k testrc4 -s 127.0.0.1 -p 8388" -a "-m rc4-md5 -k testrc4 -s 127.0.0.1 -p 8388 -l 1081"
-  - python tests/test.py -b "-m aes-256-cfb -k testrc4 -s 127.0.0.1 -p 8388" -a "-m aes-256-cfb -k testrc4 -s 127.0.0.1 -p 8388 -l 1081"
+  - python tests/test.py --with-coverage -c tests/aes.json
+  - python tests/test.py --with-coverage -c tests/aes-ctr.json
+  - python tests/test.py --with-coverage -c tests/aes-cfb1.json
+  - python tests/test.py --with-coverage -c tests/aes-cfb8.json
+  - python tests/test.py --with-coverage -c tests/rc4-md5.json
+  - python tests/test.py --with-coverage -c tests/salsa20.json
+  - python tests/test.py --with-coverage -c tests/chacha20.json
+  - python tests/test.py --with-coverage -c tests/salsa20-ctr.json
+  - python tests/test.py --with-coverage -c tests/table.json
+  - python tests/test.py --with-coverage -c tests/server-multi-ports.json
+  - python tests/test.py --with-coverage -s tests/server-multi-passwd.json -c tests/server-multi-passwd-client-side.json
+  - python tests/test.py --with-coverage -c tests/workers.json
+  - python tests/test.py --with-coverage -s tests/ipv6.json -c tests/ipv6-client-side.json
+  - python tests/test.py --with-coverage -b "-m rc4-md5 -k testrc4 -s 127.0.0.1 -p 8388" -a "-m rc4-md5 -k testrc4 -s 127.0.0.1 -p 8388 -l 1081"
+  - python tests/test.py --with-coverage -b "-m aes-256-cfb -k testrc4 -s 127.0.0.1 -p 8388" -a "-m aes-256-cfb -k testrc4 -s 127.0.0.1 -p 8388 -l 1081"
+  - coverage report --include=shadowsocks/*
diff --git a/tests/test.py b/tests/test.py
index 34c10fb..f7cc25d 100755
--- a/tests/test.py
+++ b/tests/test.py
@@ -32,18 +32,22 @@ import time
 import argparse
 from subprocess import Popen, PIPE
 
-python = 'python'
+python = ['python']
 
 parser = argparse.ArgumentParser(description='test Shadowsocks')
 parser.add_argument('-c', '--client-conf', type=str, default=None)
 parser.add_argument('-s', '--server-conf', type=str, default=None)
 parser.add_argument('-a', '--client-args', type=str, default=None)
 parser.add_argument('-b', '--server-args', type=str, default=None)
+parser.add_argument('--with-coverage', action='store_true', default=None)
 
 config = parser.parse_args()
 
-client_args = [python, 'shadowsocks/local.py', '-v']
-server_args = [python, 'shadowsocks/server.py', '-v']
+if config.with_coverage:
+    python = ['coverage', 'run', '-a']
+
+client_args = python + ['shadowsocks/local.py', '-v']
+server_args = python + ['shadowsocks/server.py', '-v']
 
 if config.client_conf:
     client_args.extend(['-c', config.client_conf])
@@ -134,6 +138,6 @@ try:
 finally:
     for p in [p1, p2]:
         try:
-            os.kill(p.pid, signal.SIGTERM)
+            os.kill(p.pid, signal.SIGQUIT)
         except OSError:
             pass