Can I change namespace of WCF ServiceContract interface without changing the service?

Is there a way to change the .NET namespace of a WCF ServiceContract Interface yet still make the WCF service backwards-compatible with clients that are using the old (identical except for namespace) ServiceContract? For example, suppose I have (in vb.net):

Namespace MyCompany.MyPoorlyNamedProject
    <ServiceContract(Name:="ThingService")> _
    <CLSCompliant(True)> _
    Public Interface IThingService
        ...
    End Interface
EndNamespace

And I want to change that to

Namespace MyCompany.MyProject
    <ServiceContract(Name:="ThingService")> _
    <CLSCompliant(True)> _
    Public Interface IThingService
        ...
    End Interface
End Namespace

Without changing the service at all.

I tried just doing so, but my xsds referred to from the wsdl show the new namespace name, which seems to be an incompatibility.

Any ideas?