diff --git a/requirements.txt b/requirements.txt
index e97eece..fe3e5e5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -20,7 +20,7 @@
 keyring>=2.1
 testrepository>=0.0.18
 oslo.config>=1.2.0
-six>=1.5.2
+six>=1.6.0
 iso8601>=0.1.9
 fixtures>=0.3.14
 testscenarios>=0.4