gob: type not registered for interface: map[string]interface {}

`gob` fails to encode `map[string]interface{}` ``` gob: type not registered for interface: map[string]interface {} ``` http://play.golang.org/p/Si4hd8I0JE ``` package main import ( "bytes" "encoding/gob" "encoding/json" "fmt" "log" ) func CloneObject(a, b interface{}) []byte { buff := new(bytes.Buffer) enc := gob.NewEncoder(buff) dec := gob.NewDecoder(buff) err := enc.Encode(a) if err != nil { log.Panic("e1: ", err) } b1 := buff.Bytes() err = dec.Decode(b) if err != nil { log.Panic("e2: ", err) } return b1 } func main() { var a interface{} a = map[string]interface{}{"X": 1} b2, err := json.Marshal(&a) fmt.Println(string(b2), err) var b interface{} b1 := CloneObject(&a, &b) fmt.Println(string(b1)) } ``` Is it possible to encode `map[string]interface{}` in gob? I am able to encode it with JSON