diff --git a/tox.ini b/tox.ini
index 7f87e2a..fb074b3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,14 +7,17 @@ deps = -r{toxinidir}/test-requirements.txt
 commands = stestr run --slowest {posargs}
 
 [testenv:pep8]
+basepython = python3
 deps=-r{toxinidir}/test-requirements.txt
 commands =
   flake8
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:docs]
+basepython = python3
 commands = python setup.py build_sphinx
 
 [flake8]