diff --git a/tox.ini b/tox.ini
index aa1860f..b7e99b5 100644
--- a/tox.ini
+++ b/tox.ini
@@ -13,25 +13,31 @@ deps = -r{toxinidir}/test-requirements.txt
 commands = python setup.py test --slowest --testr-args='{posargs}'
 
 [testenv:pep8]
+basepython = python3
 commands =
     doc8 doc/source/ CONTRIBUTING.rst HACKING.rst README.rst
     flake8
     bandit -r watcher_tempest_plugin -x tests -n5 -ll -s B320
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:cover]
+basepython = python3
 commands = python setup.py test --coverage --testr-args='{posargs}'
 
 [testenv:docs]
+basepython = python3
 commands = python setup.py build_sphinx
 
 [testenv:releasenotes]
+basepython = python3
 commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:debug]
+basepython = python3
 commands = oslo_debug_helper {posargs}
 
 [flake8]
@@ -45,6 +51,7 @@ exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build,demo/,releasenotes
 extension=.rst
 
 [testenv:bandit]
+basepython = python3
 deps = -r{toxinidir}/test-requirements.txt
 commands = bandit -r watcher_tempest_plugin -x tests -n5 -ll -s B320