diff --git a/tox.ini b/tox.ini
index d01fd0587..1f75a73c1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,34 +1,29 @@
 [tox]
-minversion = 3.18.0
+minversion = 4.6
 envlist = py3,pep8
-skipsdist = True
-# this allows tox to infer the base python from the environment name
-# and override any basepython configured in this file
-ignore_basepython_conflict=true
 
 [testenv]
-basepython = python3
-usedevelop = True
-install_command = pip install {opts} {packages}
-setenv = VIRTUAL_ENV={envdir}
-         ZAQAR_TESTS_CONFIGS_DIR={toxinidir}/zaqar/tests/etc/
-         ZAQAR_TEST_MONGODB=1
-         ZAQAR_TEST_SLOW=1
-         OS_STDOUT_CAPTURE=1
-         OS_STDERR_CAPTURE=1
-         OS_TEST_TIMEOUT=60
+usedevelop = true
+setenv =
+  VIRTUAL_ENV={envdir}
+  ZAQAR_TESTS_CONFIGS_DIR={toxinidir}/zaqar/tests/etc/
+  ZAQAR_TEST_MONGODB=1
+  ZAQAR_TEST_SLOW=1
+  OS_STDOUT_CAPTURE=1
+  OS_STDERR_CAPTURE=1
+  OS_TEST_TIMEOUT=60
 deps =
   -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/requirements.txt
 commands =
-    stestr run --serial --slowest {posargs}
+  stestr run --serial --slowest {posargs}
 
 [testenv:integration]
-setenv = {[testenv]setenv}
-         ZAQAR_TEST_INTEGRATION=1
-         OS_TEST_PATH=./zaqar/tests/functional
-commands = stestr run --serial --slowest {posargs}
+setenv =
+  {[testenv]setenv}
+  ZAQAR_TEST_INTEGRATION=1
+  OS_TEST_PATH=./zaqar/tests/functional
 
 [testenv:pep8]
 commands =
@@ -45,48 +40,49 @@ commands =
 
 [testenv:cover]
 setenv =
-    {[testenv]setenv}
-    PYTHON=coverage run --source zaqar --parallel-mode
+  {[testenv]setenv}
+  PYTHON=coverage run --source zaqar --parallel-mode
 commands =
-    {[testenv]commands}
-    coverage combine
-    coverage html -d cover
-    coverage xml -o cover/coverage.xml
+  {[testenv]commands}
+  coverage combine
+  coverage html -d cover
+  coverage xml -o cover/coverage.xml
 
 [testenv:venv]
 commands = {posargs}
 
 [testenv:docs]
 deps =
-    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
-    -r{toxinidir}/requirements.txt
-    -r{toxinidir}/doc/requirements.txt
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -r{toxinidir}/requirements.txt
+  -r{toxinidir}/doc/requirements.txt
 commands =
-    sphinx-build -W -b html doc/source doc/build/html
+  sphinx-build -W -b html doc/source doc/build/html
 
 [testenv:api-ref]
 # This environment is called from CI scripts to test and publish
 # the API Ref to docs.openstack.org.
 #
-allowlist_externals = bash
-                      rm
+allowlist_externals =
+  bash
+  rm
 deps =
-    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
-    -r{toxinidir}/doc/requirements.txt
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -r{toxinidir}/doc/requirements.txt
 commands =
-    rm -rf api-ref/build
-    sphinx-build -W -b html -d api-ref/build/doctrees api-ref/source api-ref/build/html
+  rm -rf api-ref/build
+  sphinx-build -W -b html -d api-ref/build/doctrees api-ref/source api-ref/build/html
 
 [testenv:debug]
 commands = oslo_debug_helper {posargs}
 
 [testenv:releasenotes]
 deps =
-    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
-    -r{toxinidir}/doc/requirements.txt
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -r{toxinidir}/doc/requirements.txt
 commands =
-    doc8 releasenotes/source releasenotes/notes
-    sphinx-build -a -E -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
+  doc8 releasenotes/source releasenotes/notes
+  sphinx-build -a -E -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [flake8]
 exclude = .venv*,.git,.tox,dist,doc,*lib/python*,*.egg,.update-venv