Also happening in 5.6.2 for me. I think the problem is more critical than a nuisance warning. I am issuing an update query for the mutable entity and it is not happening so my data is now incorrect. It appears as if the @Immutable annotation applies to the table, not the entity. Although sometimes it works, so it feels like which entity Hibernate chooses to look at is random? In this case it’s not looking at the entity referenced in the query.