diff --git a/tox.ini b/tox.ini
index 3fa3f85..51dfa61 100644
--- a/tox.ini
+++ b/tox.ini
@@ -19,21 +19,26 @@ commands =
   python setup.py test --slowest --testr-args='{posargs}'
 
 [testenv:pep8]
+basepython = python3
 commands = flake8
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:cover]
+basepython = python3
 commands =
   python setup.py test --coverage --testr-args='{posargs}'
   coverage report
 
 [testenv:docs]
+basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -W -b html doc/source doc/build/html
 
 [testenv:debug]
+basepython = python3
 commands = oslo_debug_helper -t karborclient/tests {posargs}
 
 [flake8]