diff --git a/requirements.txt b/requirements.txt
index 1c26578..3e05e59 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,5 +2,5 @@ cliff>=1.4.3
 PrettyTable>=0.7,<0.8
 python-keystoneclient>=0.7.0
 requests>=1.1
-six>=1.5.2
+six>=1.6.0
 Babel>=1.3