diff --git a/tox.ini b/tox.ini
index 36c84ef..5ee4ca2 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,10 +1,8 @@
 [tox]
-minversion = 3.1.0
+minversion = 4.6.0
 envlist = py3,pep8
-ignore_basepython_conflict = True
 
 [testenv]
-basepython = python3
 deps =
   -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/test-requirements.txt
@@ -35,8 +33,10 @@ commands =
 
 
 [testenv:releasenotes]
-deps = {[testenv:docs]deps}
-commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
+deps =
+  {[testenv:docs]deps}
+commands =
+  sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [flake8]
 show-source = true