diff --git a/tox.ini b/tox.ini
index b820a7c3..244be6c9 100644
--- a/tox.ini
+++ b/tox.ini
@@ -6,7 +6,7 @@ envlist = docs,linters,functional
 [testenv]
 usedevelop = True
 install_command =
-    pip install -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master} {opts} {packages}
+    pip install -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master} {opts} {packages}
 commands =
     /usr/bin/find . -type f -name "*.pyc" -delete
 passenv =