diff --git a/.travis.yml b/.travis.yml
index a6cd657b85b..1f83b8ba80c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,7 +11,7 @@ addons:
       - libssl-dev
       - libffi-dev
       - python-dev
-install: pip install --upgrade pip tox six~=1.12.0
+install: pip install --upgrade pip tox six
 cache: pip
 jobs:
   include: