diff --git a/.travis.yml b/.travis.yml
index 1f30abb..81c10cf 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -39,10 +39,16 @@ before_script:
 
 install:
   - pip2 install .
-  - pip2 install six
+  - pip2 install flake8 six
   - pip2 install -r requirements-docs.txt
   - pip2 install -r requirements-optional.txt
 
+before_script:
+  # stop the build if there are Python syntax errors or undefined names
+  - flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics
+  # exit-zero treats all errors as warnings.  The GitHub editor is 127 chars wide
+  - flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+
 script:
   - python setup.py test
   - python setup.py doc