Ihor Mochurad ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=5ccb2fc... ) *commented* on HV-1794 ( https://hibernate.atlassian.net/browse/HV-1794?atlOrigin=eyJpIjoiOTRiNDQx... ) Re: Optional containing a list of items is not being validated ( https://hibernate.atlassian.net/browse/HV-1794?atlOrigin=eyJpIjoiOTRiNDQx... ) Ok, but even if I add @Valid in front of the dto, I am getting: org.springframework.beans.InvalidPropertyException: Invalid property 'consumerGroups [0] ' of bean class [...ApplicationDTO] : Illegal attempt to get property 'consumerGroups' threw exception; nested exception is org.springframework.beans.InvalidPropertyException: Invalid property 'consumerGroups [0] ' of bean class [...ApplicationDTO] : Property referenced in indexed property path 'consumerGroups [0] ' is neither an array nor a List nor a Set nor a Map; returned value was [Optional[ [ConsumerGroupDTO(consumerGroupId=, simpleConsumerGroup=false)] ]] This seems like a bug, it doesn’t generate a proper constraint violation. ( https://hibernate.atlassian.net/browse/HV-1794#add-comment?atlOrigin=eyJp... ) Add Comment ( https://hibernate.atlassian.net/browse/HV-1794#add-comment?atlOrigin=eyJp... ) 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#100134- sha1:0043a36 )