diff --git a/lower-constraints.txt b/lower-constraints.txt
index 510b2b3d6..6e63706d5 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -128,7 +128,6 @@ rfc3986==1.1.0
 Routes==2.4.1
 simplegeneric==0.8.1
 simplejson==3.13.2
-six==1.11.0
 smmap2==2.0.3
 snowballstemmer==1.2.1
 Sphinx==1.6.5
diff --git a/requirements.txt b/requirements.txt
index c5bf3b3e4..a9d61af66 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -39,7 +39,6 @@ python-neutronclient>=6.7.0 # Apache-2.0
 python-novaclient>=14.1.0 # Apache-2.0
 python-openstackclient>=3.14.0 # Apache-2.0
 python-ironicclient>=2.5.0 # Apache-2.0
-six>=1.11.0 # MIT
 SQLAlchemy>=1.2.5 # MIT
 stevedore>=1.28.0 # Apache-2.0
 taskflow>=3.7.1 # Apache-2.0