JAX-WS and XML namespace prefixing

Question

I have a WSDL that defines a namespace like:

<wsdl:definitions
...
xmlns:mytype="urn:/some/types"
...
>

and then later targets that namespace like:

<xs:schema elementFormDefault="qualified" targetNamespace="urn:/some/types"
>
<xs:element name="MyFunction">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="element" minOccurs="1" maxOccurs="1"
        type="xs:NMTOKEN"
      />
      <xs:element name="name" minOccurs="1" maxOccurs="1" type="xs:NMTOKEN" />
    </xs:sequence>
  </xs:complexType>
</xs:element>

JAXWS then generates the following XML with auto-generated prefixes:

<S:Envelope xmlns:S="http://schemas.xmlsoap.org/soap/envelope/">
<S:Body><ns2:MyFunction xmlns:ns2="urn:/some/types" ... >
  <ns2:element>form</ns2:element>
  <ns2:name>simple</ns2:name>
</ns2:MyFunction></S:Body>
</S:Envelope>

I'm working with a server that needs the XML to use the exact prefix that was contained in the wsdl like:

<S:Envelope xmlns:S="http://schemas.xmlsoap.org/soap/envelope/">
<S:Body><mytype:MyFunction xmlns:mytype="urn:/some/types" ... >
  <mytype:element>form</mytype:element>
  <mytype:name>simple</mytype:name>
</mytype:MyFunction></S:Body>
</S:Envelope>

Is there some way I can generate this expected XML just by editing the WSDL? I know I can annotate package-info.java, but I need this done through the WSDL if possible.