diff --git a/tox.ini b/tox.ini
index 41d0691666..234e006cad 100644
--- a/tox.ini
+++ b/tox.ini
@@ -228,6 +228,7 @@ description =
 # to install (test-)requirements.txt for docs.
 deps =
   -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -r{toxinidir}/requirements.txt
   -r{toxinidir}/doc/requirements.txt
 extras =
 commands =