1 files changed, 1 insertions, 1 deletions

diff --git a/tox.ini b/tox.ini
index 4cd53b033..6a2edbffe 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,7 +16,7 @@ commands = nosetests --with-xunit \
 
 [testenv:docs]
 basepython = python2.7
-commands = sphinx-build -b html docs/api/ docs/api/_build
+commands = sphinx-build -W -b html docs/api/ docs/api/_build
 
 [testenv:pep8]
 basepython = python2.7