无法将null解码为字符串类型

I am trying to decode a struct which contains a result field, where the result field is either a null or string value. I'm trying to decode this into a string pointer but I get the error:

type MyStruct struct {
    Result   *string `json:"result,omitempty" bson:"result"`
}

The bson/json is something like:

{"result" : null}

or

{"result" : "somedata"}

Decode with:

var result MyStruct

err := collection.FindOne(ctx, filter).Decode(&result)
if err != nil {
    s.logFile.Fatal(err)
}

Error:

cannot decode null into a string type

I'm using the official driver: "github.com/mongodb/mongo-go-driver/mongo" & "github.com/mongodb/mongo-go-driver/x/bsonx"