diff --git a/tox.ini b/tox.ini
index 49c5358..34023c4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -27,6 +27,7 @@ commands = python setup.py build_sphinx --fresh-env
 
 [flake8]
 show-source = True
+enable-extensions = H106,H203
 max-line-length = 120
 exclude = .venv,.git,.tox,dist,doc,*egg,build