diff --git a/tox.ini b/tox.ini
index d5021600..d3a841fe 100644
--- a/tox.ini
+++ b/tox.ini
@@ -18,6 +18,7 @@ whitelist_externals = bash
 commands = flake8
 
 [testenv:venv]
+basepython = python2
 commands = {posargs}
 
 [testenv:docs]