re-add line I accidentally removed by hitting dd one too many times
diff --git a/tox.ini b/tox.ini
index 4a27f34..d47beac 100644
--- a/tox.ini
+++ b/tox.ini
@@ -26,6 +26,7 @@
     sphinx-build -W -b html -d {envtmpdir}/doctrees docs docs/_build/html
     sphinx-build -W -b latex -d {envtmpdir}/doctrees docs docs/_build/latex
     sphinx-build -W -b doctest -d {envtmpdir}/doctrees docs docs/_build/html
+    sphinx-build -W -b spelling docs docs/_build/html
     doc8 --allow-long-titles README.rst CHANGELOG.rst docs/ --ignore-path docs/_build/
 
 [testenv:docs-linkcheck]