orleans: Removing invalid stream subscriptions

We have cases when a grain subscribed to a stream, then this grain was refactored (the type name was renamed or the grain was removed altogether). Now every time we call stream.OnNextAsync we get errors like “Cannot find an implementation class for grain interface 213853254”

So the question is how to remove those invalid subscriptions? Is there API that could be used for that? I think it is a quite common scenario so I wonder how other people deal with it