diff --git a/tox.ini b/tox.ini
index 832a7b3..95f2cf1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 envlist = pep8,py34,py27
-minversion = 1.6
+minversion = 2.3.1
 skipsdist = True
 
 [tempestenv]