diff --git a/tox.ini b/tox.ini
index d201af1..261dec2 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-minversion = 3.9.0
+minversion = 3.18.0
 skipsdist = True
 envlist = py3,pep8
 ignore_basepython_conflict=true
@@ -49,7 +49,7 @@ deps = -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/up
 commands = sphinx-build -W -b html doc/source doc/build/html
 
 [testenv:pdf-docs]
-whitelist_externals = make
+allowlist_externals = make
 deps = {[testenv:docs]deps}
 commands = sphinx-build -b latex doc/source doc/build/pdf
            make -C doc/build/pdf