diff --git a/requirements.txt b/requirements.txt
index 61a568024..f5952540b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -9,4 +9,4 @@ oslo.utils>=1.2.0                       # Apache-2.0
 pbr>=0.6,!=0.7,<1.0
 PrettyTable>=0.7,<0.8
 python-keystoneclient>=1.1.0
-six>=1.7.0
+six>=1.9.0