diff --git a/tox.ini b/tox.ini
index 8bd65d8d..22b91366 100644
--- a/tox.ini
+++ b/tox.ini
@@ -26,7 +26,7 @@ passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
 
 [testenv:docs]
 commands = rm -rf doc/build
-           sphinx-build -E -W -b html doc/source doc/build/html
+           python setup.py build_sphinx
 
 [testenv:flake8]
 commands = flake8