Ignore error N818 about exception naming
diff --git a/tools/flake8.ini b/tools/flake8.ini
index e943b40..9b745ac 100644
--- a/tools/flake8.ini
+++ b/tools/flake8.ini
@@ -16,7 +16,8 @@
 # N801: class names should use CapWords convention
 # N802: function name should be lowercase
 # N806: variable in function should be lowercase
-ignore = E128,E129,E226,E231,E251,E265,E302,E303,E305,E402,E731,W504,W601,N801,N802,N806
+# N818: exception should be named with an Error suffix
+ignore = E128,E129,E226,E231,E251,E265,E302,E303,E305,E402,E731,W504,W601,N801,N802,N806,N818
 exclude =
     .tox,
     third_party,