diff --git a/tox.ini b/tox.ini
index bcf921b..6b2ced1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -29,5 +29,4 @@ commands = {posargs}
 
 [flake8]
 show-source = true
-builtins = _
 exclude=.venv,.git,.tox,dist,doc,*openstack/common*,*lib/python*,*egg,tools