diff --git a/tox.ini b/tox.ini
index bd1d8b0..73c19d4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -17,18 +17,23 @@ deps = -r{toxinidir}/requirements.txt
 commands = python setup.py test --slowest --testr-args='{posargs}'
 
 [testenv:pep8]
+basepython = python3
 commands = flake8 {posargs}
 
 [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]