diff --git a/requirements.txt b/requirements.txt
index e56352c..f0f44f0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -12,7 +12,7 @@ pkginfo
 ply
 python-dateutil
 s3transfer
-six
+six==1.11.0
 setuptools
 twine
 urllib3