diff --git a/setup.py b/setup.py
index d9887a8..808ec05 100644
--- a/setup.py
+++ b/setup.py
@@ -30,6 +30,7 @@ def run_tests(self):
 
 setuptools.setup(
     setup_requires=['pbr>=1.10', 'setuptools>=17.1', 'pytest-runner'],
+    install_requires=['six'],
     pbr=True,
     cmdclass={'test': PyTest},
     test_suite='tests')