diff --git a/tox.ini b/tox.ini
index f2cd638..a18cd5e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -13,7 +13,9 @@ deps = -r{toxinidir}/requirements.txt
 commands = stestr run --slowest {posargs}
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:docs]
+basepython = python3
 commands = python setup.py build_sphinx