diff --git a/tox.ini b/tox.ini
index ee6eda7a29..8ec8962d80 100644
--- a/tox.ini
+++ b/tox.ini
@@ -245,6 +245,7 @@ commands = bindep test
 
 [flake8]
 show-source = True
+enable-extensions = H203,H106
 exclude=.eggs,.git,.tox,doc
 
 [hacking]