diff --git a/tox.ini b/tox.ini
index c2f26da..707eb2f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -6,7 +6,7 @@ ignore_basepython_conflict = True
 [testenv]
 basepython = python3
 deps =
-       -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+       -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/ussuri}
        -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands = stestr run --slowest {posargs}