diff --git a/tox.ini b/tox.ini
index 8401fb1a..daf306d1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -12,7 +12,7 @@ setenv =
 passenv = *_proxy
           *_PROXY
 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
 whitelist_externals = bash