diff --git a/tox.ini b/tox.ini
index 1c8f13340..a2de8f8ac 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,16 +1,17 @@
 [tox]
-minversion = 1.6
+minversion = 1.8
 envlist = py35,py34,py27,pep8
 skipsdist = True
 
 [testenv]
 usedevelop = True
 whitelist_externals = find
-install_command = pip install -U {opts} {packages}
+install_command =
+                  constraints: pip install -U --force-reinstall -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} {opts} {packages}
+                  pip install -U {opts} {packages}
 setenv =
    VIRTUAL_ENV={envdir}
-deps = -r{toxinidir}/requirements.txt
-       -r{toxinidir}/test-requirements.txt
+deps = -r{toxinidir}/test-requirements.txt
 commands =
   find . -type f -name "*.pyc" -delete
   find . -type d -name "__pycache__" -delete