diff --git a/tox.ini b/tox.ini
index 47e4134..01fad49 100644
--- a/tox.ini
+++ b/tox.ini
@@ -33,5 +33,4 @@ commands = {posargs}
 
 [flake8]
 show-source = True
-builtins = _
 exclude=.venv,.git,.tox,dist,doc,*openstack/common*,*lib/python*,*egg,build