diff --git a/tox.ini b/tox.ini
index d8de99053..e515ed6ee 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,7 +11,7 @@ whitelist_externals = find
                     bash
 passenv = ZUUL_CACHE_DIR
           REQUIREMENTS_PIP_LOCATION
-install_command = {toxinidir}/tools/tox_install.sh {env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} {opts} {packages}
+install_command = {toxinidir}/tools/tox_install.sh {env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt?h=stable/newton} {opts} {packages}
 setenv = VIRTUAL_ENV={envdir}
          BRANCH_NAME=stable/newton
          CLIENT_NAME=python-novaclient