diff --git a/requirements.txt b/requirements.txt
index 89d1f5cdc8..720212f1f7 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -21,7 +21,7 @@ SQLAlchemy>=0.7.8,<=0.9.99
 WebOb>=1.2.3
 python-keystoneclient>=0.7.0
 alembic>=0.4.1
-six>=1.5.2
+six>=1.6.0
 stevedore>=0.14
 oslo.config>=1.2.0
 oslo.rootwrap