1 files changed, 1 insertions, 0 deletions
diff --git a/setup.py b/setup.py
index a4da6e69..c24d37c0 100644
--- a/setup.py
+++ b/setup.py
@@ -46,6 +46,7 @@ setup(
         "cryptography>=1.0",
         "passlib>=1.6.2",
         "hpack>=1.0.1",
+        "six>=1.9.0",
         "certifi"
     ],
     extras_require={