diff --git a/tox.ini b/tox.ini
index 3c2721c..2785ca8 100644
--- a/tox.ini
+++ b/tox.ini
@@ -13,19 +13,24 @@ commands = /bin/rm -f .testrepository/times.dbm
            python setup.py test --slowest --testr-args='{posargs}'
 
 [testenv:pep8]
+basepython = python3
 commands = flake8
            python setup.py check --restructuredtext --strict
 
 [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:debug]
+basepython = python3
 commands = oslo_debug_helper {posargs}
 
 [flake8]
@@ -37,4 +42,5 @@ builtins = _
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build
 
 [testenv:releasenotes]
+basepython = python3
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html