diff --git a/tox.ini b/tox.ini
index 854b4bedf..d6cb63869 100644
--- a/tox.ini
+++ b/tox.ini
@@ -13,7 +13,7 @@ passenv = *_proxy
 usedevelop = True
 install_command = pip install {opts} {packages}
 deps =
-  -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/requirements.txt
   .[influxdb,cassandra]