On the downside my fix only works with 5.0 as it makes use of something I added in 5.0. Backporting this to 4.3 would not be straight-forward; therefore the dev team have decided to not backport it. For 4.3 there is a work-around as stated above by using a Type rather than a AttributeConverter. You could even subclass org.hibernate.type.descriptor.converter.AttributeConverterTypeAdapter wrapping your AttributeConverter.