diff --git a/tox.ini b/tox.ini
index f15529cdc6..3a7ed09794 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-minversion = 2.3
+minversion = 3.1
 envlist = py37,pep8
 skipdist = True
 # Automatic envs (pyXX) will only use the python version appropriate to that