diff --git a/tox.ini b/tox.ini
index faececa3682b..85b567ec2ca9 100644
--- a/tox.ini
+++ b/tox.ini
@@ -33,6 +33,7 @@ deps =
 basepython =
     python2.7
 commands =
+    python -c "import shutil; shutil.rmtree('docs/_build')"
     sphinx-build -W -b html -d docs/_build/doctrees docs docs/_build/html
 deps =
     Sphinx