diff --git a/requirements.txt b/requirements.txt
index 79887e202..caed2a785 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -14,5 +14,5 @@ oslo.serialization>=1.2.0               # Apache-2.0
 oslo.utils>=1.2.0                       # Apache-2.0
 PrettyTable>=0.7,<0.8
 requests>=2.2.0,!=2.4.0
-six>=1.7.0
+six>=1.9.0
 stevedore>=1.1.0  # Apache-2.0