diff --git a/tox.ini b/tox.ini
index 82dba92..d37c226 100644
--- a/tox.ini
+++ b/tox.ini
@@ -147,6 +147,7 @@
 ignore = E125,E123,E129
 show-source = True
 exclude = .git,.venv,.tox,dist,doc,*egg
+enable-extensions = H106,H203
 
 [testenv:releasenotes]
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html