Thank you for your input. I tried it. It kind of works, but I find the behaviour strange. Can you please take a look?

I added the annotation and the "Child"-entity is not eagerly loaded, so far so good. But I noticed that the query to fetch the "Parent" has changed to:

2016-07-13 18:15:58,869 DEBUG org.hibernate.SQL - select parent0_.id as id1_1_0_ from Parent parent0_ where parent0_.id=?

The child_id column is no longer included. When I now access the child two queries are executed:

2016-07-13 18:15:58,882 DEBUG org.hibernate.SQL - select parent_.child_id as child_id2_1_ from Parent parent_ where parent_.id=?
2016-07-13 18:15:58,884 DEBUG org.hibernate.SQL - select child0_.id as id1_0_0_ from Child child0_ where child0_.id=?

Is that expected behaviour?