diff --git a/requirements.txt b/requirements.txt
index d0ef3c5..1aa2e7a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
 pbr>=0.6,!=0.7,<1.0
 Django>=1.4,<1.7
 python-keystoneclient>=0.7.0
-six>=1.5.2
+six>=1.6.0