diff --git a/tox.ini b/tox.ini
index 521f07b..7ed8e38 100644
--- a/tox.ini
+++ b/tox.ini
@@ -44,5 +44,5 @@ whitelist_externals =
 commands =
     sphinx-apidoc -o "./docs/" "keyosk"
     rm "docs/modules.rst"
-    sphinx-build -M html "./docs/" "./docs/_build"
-    sphinx-build -M latex "./docs/" "./docs/_build"
+    sphinx-build -M html "./docs/" "./docs/_build" -W
+    sphinx-build -M latex "./docs/" "./docs/_build" -W