AttributeMapper makes use of getDelcaredField() which has very onerous requirements of field visibility and inherited fields. Personally I find the whole approach taken by the AttributeMapper to be too heavy handed and would like to be able to easily specify that any type that can be handled by a SingleValueConverter should be written/read as an attribute. Up until the 1.2..2-SNAPSHOT the following approach worked well, I simply added the following MapperWrapper and class MyAttributeMapper extends MapperWrapper { XStream xStream; public MyAttributeMapper(Mapper wrapped, XStream xStream) { super(wrapped); this.xStream = xStream; } protected SingleValueConverter getLocalConverterFromItemType(Class type) { Converter converter = xStream.getConverterLookup().lookupConverterForType(type); if (converter != null && converter instanceof SingleValueConverter) { return (SingleValueConverter)converter; } else { return null; } } public SingleValueConverter getConverterFromItemType(Class type) { return getLocalConverterFromItemType(type); } } However testing with 1.2.2-SNAPSHOT our entire application bombs because of the added restriction introduced by the use of getDeclaredField() in AttributeMapper, as an example, see the following test :