JAXB: How can I unmarshal XML without namespaces

I have an XML file:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<object>
   <str>the type</str>
   <bool type="boolean">true</bool>        
</object>

And I want to unmarshal it to an object of the class below

@XmlRootElement(name="object")
public class Spec  {
   public String str;
   public Object bool;

}

How can I do this? Unless I specify namespaces (see below), it doesn't work.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<object>
   <str>the type</str>
   <bool xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   
       xmlns:xs="http://www.w3.org/2001/XMLSchema"  
       xsi:type="xs:boolean">true</bool>        
</object>