WCF - wsdl files getting generated each time I change the endpoint url.

In my project, I have service reference. In this service reference, I connect to a service. We have different development boxes and each box has a different version of the service. So dev1.somecompany.com may not have the exact same version as dev2.somecompany.com
Attachment 105927
As a result, every time I hit the Update Service Reference button, a new WSDL file gets generated to the ServiceReferences folder.
Example: previous file is AuthenticateSvc.wsdl
file generated second time is AuthenticateSvc1.wsdl

Though this is not a show-stopper, it is becoming increasingly difficult to track changes in the wsdl via TFS, since now there are several iterations of the .wsdl file.
Is there someway I can force Visual Studio 2012 to overwrite the current wsdl file?