Filip Procházka ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) *updated* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiYTdhNjU2N2Yw... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-14151?atlOrigin=eyJpIjoiYTdhNj... ) HHH-14151 ( https://hibernate.atlassian.net/browse/HHH-14151?atlOrigin=eyJpIjoiYTdhNj... ) SingularAttribute.isOptional() does not honour javax.validation.constraints.NotNull ( https://hibernate.atlassian.net/browse/HHH-14151?atlOrigin=eyJpIjoiYTdhNj... ) Change By: Filip Procházka ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) I've just upgraded Spring Boot, which upgraded Hibernate ORM from 5.4.12.Final to 5.4.18.Final I have an association {code:java} @javax.persistence.ManyToOne(fetch = FetchType.LAZY) @javax.validation.constraints.NotNull private Product product; {code} I have logic that inspects metadata and collects nullable associations of an entity {code:java} List<Attribute<?, ?>> fields = new ArrayList<>(); fields.addAll(entityType.getSingularAttributes().stream() .filter(singularAttribute -> singularAttribute.isAssociation() && singularAttribute.getType() instanceof EntityType && singularAttribute.isOptional()) .collect(Collectors.toList())); return fields; {code} where `entityType` is `javax.persistence.metamodel.EntityType` Previously, the `isOptional` honoured the `NotNull` constraint and returned false, not now it returns true which breaks my logic. I'm not yet sure if this is a miss-configuration by Spring Boot or by my application or if it's a bug in Hibernate, but with the upgrade this changed unexpectedly. ( https://hibernate.atlassian.net/browse/HHH-14151#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-14151#add-comment?atlOrigin=ey... ) Get Jira notifications on your phone! Download the Jira Cloud app for Android ( https://play.google.com/store/apps/details?id=com.atlassian.android.jira.... ) or iOS ( https://itunes.apple.com/app/apple-store/id1006972087?pt=696495&ct=Em... ) This message was sent by Atlassian Jira (v1001.0.0-SNAPSHOT#100144- sha1:57e1ab7 )