diff --git a/tox.ini b/tox.ini
index b3629e8..005e371 100644
--- a/tox.ini
+++ b/tox.ini
@@ -20,6 +20,7 @@ basepython = python3
 commands = sphinx-build -W -b html doc/source doc/build/html
 
 [testenv:spelling]
+basepython = python3
 deps =
    -r{toxinidir}/requirements.txt
    sphinxcontrib-spelling