diff --git a/tox.ini b/tox.ini
index 193da70..85c2ac6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -19,23 +19,28 @@ deps =
 commands = pifpaf run aodh -- python setup.py test --slowest --testr-args='{posargs}'
 
 [testenv:pep8]
+basepython = python3
 deps = hacking<0.13,>=0.12
 commands = flake8
 
 [testenv:venv]
+basepython = python3
 # Used by openstack-infra to build the doc
 deps = -r{toxinidir}/doc/requirements.txt
 commands = {posargs}
 
 [testenv:cover]
+basepython = python3
 commands =
    python setup.py test --coverage --testr-args='{posargs}'
    coverage report
 
 [testenv:releasenotes]
+basepython = python3
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:docs]
+basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 commands =
    rm -rf doc/build
@@ -43,6 +48,7 @@ commands =
 whitelist_externals = rm
 
 [testenv:debug]
+basepython = python3
 commands = pifpaf --debug run aodh -- oslo_debug_helper {posargs}
 
 [flake8]