diff --git a/tox.ini b/tox.ini
index 048d70b..410337a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,7 +1,8 @@
 [tox]
-minversion = 2.0
+minversion = 3.1.0
 envlist = py3,py27,pep8
 skipsdist = True
+ignore_basepython_conflict=true
 
 [testenv]
 usedevelop = True