I have a similar question: I am changing the requires_grad of module parameters after wrapping with DataParallel. In DistributedDataParallel 4, which is now recommended instead of DataParallel, there is a warning that says “don’t do it!”. But I do not see the same warning for DataParallel. I agree that the proper way is to re-wrap it after the change, but that is a little more code.