General subclasses of the @objc classes cannot have the explicit @objc attribute

Question

I am trying to add a quick library to my objective project with https://github.com/vimeo/VimeoUpload

I already added #import "-Swift.h" in my project to a subclass of VimeoUpload, I add @objc in the class definition and this gives me the following error

"General subclasses of @objc classes cannot have an explicit @objc attribute because they are not visible directly from Objective-C."

Can someone help me fix this?