diff --git a/tox.ini b/tox.ini
index 51719be..07bb7ae 100644
--- a/tox.ini
+++ b/tox.ini
@@ -19,14 +19,17 @@ commands =
   stestr slowest
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:docs]
+basepython = python3
 commands =
   find . -type f -name "*.py[c|o]" -delete
   python setup.py build_sphinx
 
 [testenv:pep8]
+basepython = python3
 deps = -r{toxinidir}/test-requirements.txt
 commands =
   flake8 {posargs}