diff --git a/.travis.yml b/.travis.yml
index ab7da064..d254bd80 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,7 +3,7 @@ sudo: false
 python:
 - 2.7
 install:
-- pip install pytest pytest-cov coveralls flake8
+- pip install pytest pytest-cov coveralls flake8 six
 - pip install git+https://github.com/dittos/graphqllib.git # Last version of graphqllib
 - pip install graphql-relay
 - python setup.py develop
diff --git a/setup.py b/setup.py
index 7925712f..b5222dc0 100644
--- a/setup.py
+++ b/setup.py
@@ -47,6 +47,7 @@ setup(
     packages=find_packages(exclude=['tests']),
 
     install_requires=[
+        'six',
         'graphqllib',
         'graphql-relay'
     ],