diff --git a/tox.ini b/tox.ini
index a089625f..95026545 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,12 +7,12 @@ ignore_basepython_conflict = True
 usedevelop = True
 basepython = python3
 setenv =
-   VIRTUAL_ENV={envdir}
-   OS_TEST_PATH=./castellan/tests/unit
+  VIRTUAL_ENV={envdir}
+  OS_TEST_PATH=./castellan/tests/unit
 deps =
-       -c{env:TOX_CONSTRAINTS_FILE:https://opendev.org/openstack/requirements/raw/branch/master/upper-constraints.txt}
-       -r{toxinidir}/requirements.txt
-       -r{toxinidir}/test-requirements.txt
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -r{toxinidir}/requirements.txt
+  -r{toxinidir}/test-requirements.txt
 commands = stestr run --slowest --concurrency=1 {posargs}
 
 [testenv:pep8]
@@ -53,10 +53,12 @@ commands =
 # This environment is called from CI scripts to test and publish
 # the main docs to https://docs.openstack.org/castellan
 description = Build main documentation
-deps = -r{toxinidir}/doc/requirements.txt
+deps =
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -r{toxinidir}/doc/requirements.txt
 commands=
-    rm -rf doc/build doc/build/doctrees
-    sphinx-build -W -b html -d doc/build/doctrees doc/source doc/build/html
+  rm -rf doc/build doc/build/doctrees
+  sphinx-build -W -b html -d doc/build/doctrees doc/source doc/build/html
 allowlist_externals = rm
 
 [testenv:pdf-docs]