How to stub toJSON method created with Mongoose set() method

I am looking for a way to stub the "toJSON" method.

ModelSchema.set("toJSON", {
  transform(doc, ret) {
    const { _id: id, __v, ...others } = ret;
    return { id, ...others };
  },
});

I have tried doing.

sinon.stub(Modelname, "toJSON")

But sinon throws an error saying

Cannot stub non-existent own property toJSON

Does anyone have any idea on how to stub this method, any help is greatly appreciated