Combining Choice with Any fails to marshal without #XmlRootElement - jaxb

Question

I'm using JAX-B to generate POJOs from a predefined XSD.
I encountered this element definition
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns="http://order.example.com"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://order.example.com"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<xs:element name="Order">
<xs:complexType>
<xs:sequence>
<xs:choice maxOccurs="unbounded">
<xs:choice minOccurs="0" maxOccurs="3">
<xs:element name="Credit" type="CreditType" form="qualified"/>
<xs:element name="GiftCard" type="GiftCardType" form="qualified"/>
</xs:choice>
<xs:any namespace="##other" processContents="lax"/>
</xs:choice>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:complexType name="CreditType">
<xs:sequence>
<xs:element name="Number" type="xs:string" />
</xs:sequence>
</xs:complexType>
<xs:complexType name="GiftCardType">
<xs:sequence>
<xs:element name="Code" type="xs:long" />
</xs:sequence>
</xs:complexType>
</xs:schema>
As you notice there's an awful combination of a nested <choice/> with <any/>.
XJC generates this code:
#XmlAccessorType(XmlAccessType.FIELD)
#XmlType(name = "", propOrder = {
"creditOrGiftCardOrAny"
})
#XmlRootElement(name = "Order")
public class Order {
#XmlElementRefs({
#XmlElementRef(name = "GiftCard", namespace = "http://order.example.com", type = JAXBElement.class, required = false),
#XmlElementRef(name = "Credit", namespace = "http://order.example.com", type = JAXBElement.class, required = false)
})
#XmlAnyElement(lax = true)
protected List<Object> creditOrGiftCardOrAny;
}
Where the property references JAXBElements instead of the generated classes of CreditType and GiftCardType.
If I try to marshal an Order object like this:
Order order = new Order();
CreditType credit = new CreditType();
credit.setNumber("4111111111111111");
order.getCreditOrGiftCardOrAny().add(credit);
JAXBContext jaxbContext = JAXBContext.newInstance(Order.class);
Marshaller marshaller = jaxbContext.createMarshaller();
marshaller.marshal(order, System.out);
I get the following error:
[com.sun.istack.internal.SAXException2: unable to marshal type "com.example.order.CreditType" as an element because it is missing an #XmlRootElement annotation]
Which can be solved by adding a binding that forces XJC to annotate the class, the problem is that in my case I have many occurrences of this issue and so having to add a binding for each type doesn't scale very well.
Anyone has a better suggestion?
I uploaded a maven project reproducing the issue: https://github.com/jcfandino/jaxb-choice
Just run:
git clone https://github.com/jcfandino/jaxb-choice.git && cd jaxb-choice
mvn test