How to make JAXB unmarshaller to ignore prefixes?

I have the following XML:

<ns2:Person name="John" age="20" />

And I want to unmarshal it to JAXB object Person which was generated from the XSD.

this is the code I'm running:

JAXBContext context = JAXBContext.newInstance(PersoEntity.class);
Unmarshaller um = context.createUnmarshaller();
StringReader sr = new StringReader(xml);
Person p = (Person)um.unmarshal(sr);

Surprisingly I get the following exception:

javax.xml.bind.UnmarshalException
 - with linked exception:
[org.xml.sax.SAXParseException: The prefix "ns2" for element "ns2:Person" is not bound.]

How do I solve it? Thanks