diff --git a/tox.ini b/tox.ini
index 10c7f301a..51caec89d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-minversion = 1.6
+minversion = 2.3.1
 envlist = py34,py27,pep8
 skipsdist = True