diff --git a/.travis.yml b/.travis.yml
index 6c9a2cf..d7871d8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,6 +3,8 @@ language: python
 python:
 - 2.7
 - 3.5
+install:
+- pip install tox
 script:
 - tox
 branches: