diff --git a/tox.ini b/tox.ini
index 8432eb53a..29d1c0a72 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 minversion = 1.6
-envlist = pep8, py34, py35, py27
+envlist = docs, pep8, py35, py27, cover
 skip_missing_interpreters = true
 
 [testenv]