diff --git a/requirements-nover.txt b/requirements-nover.txt
index fe9657b89..6fe50fc80 100644
--- a/requirements-nover.txt
+++ b/requirements-nover.txt
@@ -51,3 +51,4 @@ python-swiftclient
 python-keystoneclient
 Flask-Testing
 pyjwt
+toposort
diff --git a/requirements.txt b/requirements.txt
index d5d8cd2b4..1061d96e9 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -79,6 +79,7 @@ SQLAlchemy==1.0.6
 stevedore==1.5.0
 stringscore==0.1.0
 stripe==1.22.3
+toposort==1.4
 trollius==1.0.4
 tzlocal==1.2
 urllib3==1.10.4