diff --git a/tox.ini b/tox.ini
index 9f63146c..1308456e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -21,38 +21,46 @@ commands =
 whitelist_externals = rm
 
 [testenv:releasenotes]
+basepython = python3
 commands = sphinx-build -a -W -E -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:pep8]
+basepython = python3
 deps =
     -r{toxinidir}/test-requirements.txt
 commands = flake8
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:cover]
+basepython = python3
 commands =
   python setup.py testr --coverage --testr-args='{posargs}'
   coverage report --fail-under=71 --skip-covered
 
 [testenv:genconfig]
+basepython = python3
 deps =
     -r{toxinidir}/test-requirements.txt
 commands = oslo-config-generator --config-file=etc/api-cfg-gen.conf
            oslo-config-generator --config-file=etc/xjob-cfg-gen.conf
 
 [testenv:genpolicy]
+basepython = python3
 deps =
     -r{toxinidir}/test-requirements.txt
 commands = oslopolicy-sample-generator --config-file=etc/policy-generator.conf
 
 [testenv:docs]
+basepython = python3
 deps =
     -r{toxinidir}/test-requirements.txt
 commands = python setup.py build_sphinx
 
 [testenv:debug]
+basepython = python3
 commands = oslo_debug_helper {posargs}
 
 [flake8]