Migrating a blueprint based on a custom class breaks after migration

When a blueprint that is based on a custom class is migrated from one project to another the references to the original class are held. This means that the blueprint is unusable in the new project, even if the code class is migrated over as well.

1. Open UE4 Editor (any Project)
2. Create a class based on Actor (MyActor)
3. Create a blueprint based on MyActor (MyActorBP)
4. Right click MyActorBP in the content browser and select Asset Actions->Migrate
5. Select a project to migrate MyActorBP to.
6. After Migrating, open the project that MyActorBP migrated to
7. Find MyActorBP in the content browser and double click to open it.

Result:
Opening the BP fails with error saying that the parent class is invalid.