diff --git a/tox.ini b/tox.ini
index eea97fc..2cb62d0 100644
--- a/tox.ini
+++ b/tox.ini
@@ -24,5 +24,4 @@ commands =
 
 [flake8]
 show-source = true
-builtins = _
 exclude=.git,.tox,dist,doc,*openstack/common*,*lib/python*,*egg