diff --git a/.travis.yml b/.travis.yml
index ef3ec362c41..eeeaee85df8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -85,6 +85,7 @@ before_install:
 # Install various dependencies
 install:
   - pip install --upgrade pip
+  - pip install --upgrade six
   - pip install --upgrade setuptools
   - pip install --upgrade codecov
   - pip install --upgrade flake8