diff --git a/setup.cfg b/setup.cfg
index 8c7ad2df..aaae0b06 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -6,6 +6,7 @@ description-file =
 author = OpenStack Documentation
 author-email = openstack-discuss@lists.openstack.org
 home-page = https://docs.openstack.org/openstack-doc-tools/latest/
+python-requires = >=3.6
 classifier =
     Environment :: OpenStack
     Intended Audience :: Information Technology