diff --git a/tox.ini b/tox.ini
index 1587123dc..97b845e2c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -13,25 +13,31 @@ commands = python setup.py test --slowest --testr-args='{posargs}'
 whitelist_externals = bash
 
 [testenv:releasenotes]
+basepython = python3
 whitelist_externals = bash
 commands = bash -c tools/releasenotes_tox.sh
 
 [testenv:pep8]
+basepython = python3
 commands =
     {[testenv:ansible-lint]commands}
     flake8 {posargs}
     python ./tools/validate-files.py .
 
 [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}
 
 [testenv:ansible-lint]