diff --git a/tox.ini b/tox.ini
index e4707570..5c8880e6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -23,6 +23,7 @@ commands =
     yaml2ical -y meetings -i output/calendars/ -f
 
 [testenv:pep8]
+basepython = python3
 whitelist_externals = bash
 commands =
   bash test_tools/flake8wrap.sh {posargs}