diff --git a/.travis.yml b/.travis.yml
index 28d37e98..e630053c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -12,7 +12,7 @@ install:
   - pip install flake8
 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
+  - flake8 . --count --select=E901,E999,F821,F822,F823,F401,F403,F405 --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: