This is the correct behavior, really. Bulk insert is not for cases where you have complex per-record validation or processing logic that also needs to be run in the application layer. It's for "I have all this data ready to go, now just shove it in there as efficiently as possible". If you need to have validation and additional per-record processing, signals, etc., insert the objects through the ORM normally. Yes, it'll be slower, but that's the price you pay for doing per-record processing.