diff --git a/tox.ini b/tox.ini
index 9aa7070..e4f4e76 100644
--- a/tox.ini
+++ b/tox.ini
@@ -14,6 +14,7 @@ show-source = 1
 statistics = 1
 
 [tox]
+minversion=1.8
 envlist =
     pep8, py{26,27,33,34,py}-{selects,poll,epolls}, py{27,34,py}-dns