diff --git a/tox.ini b/tox.ini
index 21ba7ed..02c0531 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,7 +1,7 @@
 [tox]
 minverson = 1.6
 skipsdist = True
-envlist = py27, pep8
+envlist = py27, pep8, docs
 
 [testenv]
 deps = -r{toxinidir}/requirements.txt
@@ -15,5 +15,8 @@ commands = flake8
 [testenv:venv]
 commands = {posargs}
 
+[testenv:docs]
+commands = python setup.py build_sphinx
+
 [flake8]
 exclude = .tox