diff --git a/tox.ini b/tox.ini
index 2b8e6c39..b38ea0e4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,9 +8,8 @@ ignore_basepython_conflict = True
 basepython = python3
 usedevelop = True
 setenv =
-  CONSTRAINTS_OPT=-c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
 deps =
-  {env:CONSTRAINTS_OPT}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/requirements.txt
   -r{toxinidir}/test-requirements.txt
 commands = stestr run --black-regex ".tests.functional" {posargs}
@@ -24,7 +23,7 @@ commands =
 
 [testenv:docs]
 deps =
-  {env:CONSTRAINTS_OPT}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -W -b html doc/source doc/build/html