diff --git a/requirements.txt b/requirements.txt
index b220839c..0fecc34e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -35,5 +35,5 @@ python-subunit>=0.0.18
 requests>=2.2.0,!=2.4.0
 SQLAlchemy>=0.9.7,<=0.9.99
 sphinx>=1.1.2,!=1.2.0,!=1.3b1,<1.3
-six>=1.7.0
+six>=1.9.0
 WSME>=0.6