When using @ElementCollection with Set = SetOf() I get org.hibernate.NotYetImplementedFor6Exception: Only support for basic-valued, entity-valued and embedded model-parts have been implemented : userNames [PluralAttribute]

This worked before upgrading to hibernate 6

@SqlResultSetMappings(
SqlResultSetMapping(
name = "Mapping.User",
entities = [
EntityResult(
entityClass = User::class,
fields = [
FieldResult(name = "id", column = "id"),
FieldResult(name = "userNames", column = "user_names"),
]
)
],

),
SqlResultSetMapping(
name = "Mapping.User.count",
columns = [ColumnResult(name = "rowCount")]
)
)

@Entity
@Table(name = "users")
data class User(
@Id
@GeneratedValue(generator = "UUID")
@GenericGenerator(
name = "UUID",
strategy = "org.hibernate.id.UUIDGenerator"
)
@Column(name = "id")
var id: UUID = UUID.randomUUID(),@ElementCollection(fetch = FetchType.EAGER)
@CollectionTable(
name = "users_names",
joinColumns = [JoinColumn(name = "user_id", referencedColumnName = "id")]
)
@Column(name = "user_names")
var userNames: Set<String> = setOf(),

)