external library with un-serialized sealed class

I have an external library I am using within my project which contains an event class which I display on a databound server control on my page. Currently the event class in the external library is not marked as serializable so if I enable view state on my server control then an error is thrown saying that the event object could not be serialised.

Unfortunately the event class in the library is also marked as sealed so I can not inherit this in to another class and mark the new class as serialized.

Any ideas as to how I can enable serialization for this object?