diff --git a/requirements.txt b/requirements.txt
index f4abba3cf8..d7a9f6f6ed 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -38,6 +38,6 @@ python-keystoneclient>=0.7.0
 pyOpenSSL>=0.11
 
 # Required by openstack.common libraries
-six>=1.5.2
+six>=1.6.0
 
 oslo.messaging>=1.3.0a9