When using the @SortNatural annotation, the application fails with the exception:

Caused by: org.hibernate.AnnotationException: A sorted collection must define and ordering or sorting : com.doblones.data.StockSummarySegment.summaries
at org.hibernate.cfg.annotations.CollectionBinder.applySortingAndOrdering(CollectionBinder.java:603)
at org.hibernate.cfg.annotations.CollectionBinder.bind(CollectionBinder.java:447)
at org.hibernate.cfg.AnnotationBinder.processElementAnnotations(AnnotationBinder.java:2027)
at org.hibernate.cfg.AnnotationBinder.processIdPropertiesIfNotAlready(AnnotationBinder.java:834)
at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:753)
at org.hibernate.cfg.Configuration$MetadataSourceQueue.processAnnotatedClassesQueue(Configuration.java:3762)
at org.hibernate.cfg.Configuration$MetadataSourceQueue.processMetadata(Configuration.java:3716)
at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1410)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1844)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:850)
... 53 more

Code is:

@OneToMany(mappedBy = "segment", fetch = FetchType.EAGER, cascade =

)
@SortNatural
private SortedSet<StockSummary> summaries;

If I revert to the deprecated @Sort annotation, it works fine.