diff --git a/setup.cfg b/setup.cfg
index 87ef81ede..df31020c3 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,7 +1,7 @@
 [flake8]
 max-line-length = 140
 max-complexity = 25
-ignore = E251,C901
+ignore = E251,C901,W503
 exclude = mitmproxy/contrib/*,test/mitmproxy/data/*
 addons = file,open,basestring,xrange,unicode,long,cmp