1 files changed, 2 insertions, 0 deletions
diff --git a/tox.ini b/tox.ini
index ac5c6593..0f22650a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -85,6 +85,8 @@ commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasen
 
 [flake8]
 show-source = True
+# H203: Use assertIs(Not)None to check for None
+enable-extensions = H203
 exclude = .git,.tox,dist,doc,*lib/python*,*egg,build,tools
 # If 'ignore' is not set there are default errors and warnings that are set
 # Doc: http://flake8.readthedocs.org/en/latest/config.html#default