@djcp, OK I understand but another question that why don't we add errors only on the `base_attr_name` then? I think you are adding errors on `attr_name` to make it more readable i.e. `Attachment file size must be less than 10 Mb` instead of `Attachment must be less than 10 Mb`. If that's the case then we can only add the error on `base_attr_name` and add a message to our en.yml file to show the more readable message. Code that needs to be added to en.yml for this purpose should look like this.

```
en:
  errors:
    messages:
      less_than: 'file size must be less than %{count}'
```

In this way, we are not adding errors to `attr_name` so the error messages will not be duplicated and paperclip will be easily able to handle with simpleform and other form builder gems because we added the error to `base_attr_name`.