diff --git a/.travis.yml b/.travis.yml
index e6563f0fe..aa875cc38 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,6 +14,7 @@ install:
   - pip install -r requirements.txt
 
 script:
+  - flake8 tests/
   - py.test
   - python -m doctest -v *.py