WCF service not returning the correct json format

Hi everybody,
I have created a WCF service and it is returning the json in the format below, how can I get rid of "d":{"__type":"CustomerEntity:#TimeTrakker" in the string and just get a regular json string back?

{"d":{"__type":"CustomerEntity:#TimeTrakker", "Pk":1,"UserId":"0 ","LastName":"Strahl", "FirstName":"Rick","Company":"West Win ...