diff --git a/tox.ini b/tox.ini
index d8e95b3..477e063 100644
--- a/tox.ini
+++ b/tox.ini
@@ -22,16 +22,20 @@ deps =  {env:CONSTRAINTS_OPT}
 whitelist_externals = sh
 
 [testenv:pep8]
+basepython = python3
 commands = flake8 collectd_openstack
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:docs]
+basepython = python3
 #fixeme(sean-k-mooney): add -W to treat warnings as errors once warnings are fixed
 commands = sphinx-build doc/source doc/build
 
 [testenv:releasenotes]
+basepython = python3
 #fixeme(sean-k-mooney): add -W to treat warnings as errors once warnings are fixed
 #NOTE(sean-k-mooney): our releasenotes crash sphinx so we should really fix them ...
 commands =