diff --git a/tox.ini b/tox.ini
index 07f3f9e..f1658e5 100644
--- a/tox.ini
+++ b/tox.ini
@@ -17,24 +17,30 @@ deps =
 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 = {toxinidir}/tools/cover.sh {posargs}
 
 [testenv:docs]
+basepython = python3
 commands =
     python tools/gen_errors.py
     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 =
     find . -type f -name "*.pyc" -delete
     oslo_debug_helper -t muranopkgcheck/tests {posargs}