diff --git a/tox.ini b/tox.ini
index 100b68a..70d2b3e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -6,7 +6,7 @@ envlist = py27,py37,pep8
 [testenv]
 usedevelop = True
 deps =
-       -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+       -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/train}
        -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 install_command = pip install {opts} {packages}