diff --git a/tox.ini b/tox.ini
index 4581bbc15..ef8760092 100644
--- a/tox.ini
+++ b/tox.ini
@@ -32,7 +32,7 @@ passenv =
     SSL_CERT_FILE
     TERM
 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}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands = stestr run {posargs}