diff --git a/tox.ini b/tox.ini
index 760cc47..eecd16e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -53,7 +53,8 @@
 # E128 continuation line under-indented for visual indent
 # E129 visually indented line with same indent as next logical line
 # N530 direct neutron imports not allowed
-ignore = E126,E128,E129,N530
+# W504 line break after binary operator
+ignore = E126,E128,E129,N530,W504
 # H106: Don't put vim configuration in source files
 # H203: Use assertIs(Not)None to check for None
 # H204: Use assert(Not)Equal to check for equality