diff --git a/.travis.yml b/.travis.yml
index e36c641..46419ea 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,10 +9,11 @@ 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
+  - pip install m2crypto salsa20 pep8 nose
   - sudo tests/socksify/install.sh
 script:
   - pep8 .
+  - nosetests shadowsocks/*
   - python tests/test.py -c tests/table.json
   - python tests/test.py -c tests/aes.json
   - python tests/test.py -c tests/aes-ctr.json
diff --git a/tests/test_latency.py b/tests/test_latency.py
index 26df542..5d44644 100644
--- a/tests/test_latency.py
+++ b/tests/test_latency.py
@@ -4,9 +4,10 @@ import sys
 import time
 
 
-before = time.time()
+if __name__ == '__main__':
+    before = time.time()
 
-for line in sys.stdin:
-    if 'HTTP/1.1 ' in line:
-        diff = time.time() - before
-        print 'headline %dms' % (diff * 1000)
+    for line in sys.stdin:
+        if 'HTTP/1.1 ' in line:
+            diff = time.time() - before
+            print 'headline %dms' % (diff * 1000)