Frank Kelly ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=712020%... ) *commented* on HHH-16916 ( https://hibernate.atlassian.net/browse/HHH-16916?atlOrigin=eyJpIjoiMzc4Zj... ) Re: OneToOne relationships don't work in Hibernate 6.x anymore ( https://hibernate.atlassian.net/browse/HHH-16916?atlOrigin=eyJpIjoiMzc4Zj... ) I think I am seeing the same - have you tried lowering the Hibernate version to (say) 6.1.7.Final just to help isolate where in 6.x For me the issue goes away when I change the @OneToOne to @ManyToOne - not clear if that was the intent from the start so waiting for confirmation from another engineer on my team. ( https://hibernate.atlassian.net/browse/HHH-16916#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16916#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#100232- sha1:4329f54 )