diff --git a/tox.ini b/tox.ini
index df8ef8e..a72ee83 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,7 +1,10 @@
 [tox]
-minversion = 2.0
-envlist = py37,pep8
-skipsdist = True
+minversion = 3.1.1
+envlist = py36,py37,py38,pep8
+# Automatic envs (pyXX) will only use the python version appropriate to that
+# env and ignore basepython inherited from [testenv] if we set
+# ignore_basepython_conflict.
+ignore_basepython_conflict = True
 
 [testenv]
 basepython = python3