diff --git a/requirements.txt b/requirements.txt
index e11aefad11..089e0635bb 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -28,7 +28,7 @@ oslo.serialization>=1.2.0               # Apache-2.0
 oslo.utils>=1.2.0                       # Apache-2.0
 pecan>=0.8.0
 requests>=2.2.0,!=2.4.0
-six>=1.7.0
+six>=1.9.0
 jsonpatch>=1.1
 WSME>=0.6
 Jinja2>=2.6  # BSD License (3 clause)