JAXB - Move dynamically generated namespaces to document root

I've got this POJO:

public class SimpleElement {

    private Namespace namespace;
    private String tagName;
    private String value;
    private Collection<Attribute> attributes;

    /* getters/setters/... */

And for completeness, Attribute

public class Attribute {

    private String name;
    private String value;
    private Namespace namespace;  

And Namespace:

public class Namespace {

    private final String uri;
    private final String prefix;

SimpleElementAdapter serializes a SimpleElement into its org.w3c.dom.Element counterpart.

The only problem with this approach is that namespaces always end up at element level, never at document root.

Is there a way to dynamically declare namespaces at document root?