diff --git a/lower-constraints.txt b/lower-constraints.txt
index 0d0c560798..010c4a795b 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -35,7 +35,7 @@ python-openstackclient==3.16.0
 reno==2.5.0
 requests==2.14.2
 requests-mock==1.2.0
-six==1.10.0
+six==1.11.0
 SQLAlchemy==1.2.0
 sphinx==1.6.5
 stestr==1.0.0
diff --git a/requirements.txt b/requirements.txt
index 0f43300a37..ece9218890 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -9,7 +9,7 @@ requests>=2.14.2 # Apache-2.0
 netaddr>=0.7.18 # BSD
 tenacity>=4.9.0 # Apache-2.0
 SQLAlchemy!=1.1.5,!=1.1.6,!=1.1.7,!=1.1.8,>=1.2.0 # MIT
-six>=1.10.0 # MIT
+six>=1.11.0 # MIT
 stevedore>=1.20.0 # Apache-2.0
 neutron-lib>=1.26.0 # Apache-2.0
 osc-lib>=1.10.0 # Apache-2.0