diff --git a/subscribe/message.go b/subscribe/message.go
index 5d1a346..40315b1 100644
--- a/subscribe/message.go
+++ b/subscribe/message.go
@@ -47,7 +47,7 @@ func (st TargetType) String() string {
 func (st *TargetType) MarshalJSON() ([]byte, error) {
 	value, ok := targetTypeID[*st]
 	if !ok {
-		return nil, fmt.Errorf("Invalid EnumType[%s] value", st)
+		return nil, fmt.Errorf("Invalid EnumType[%s] value", *st)
 	}
 	return json.Marshal(value)
 }
@@ -64,6 +64,6 @@ func (st *TargetType) UnmarshalJSON(b []byte) error {
 	if !ok {
 		return fmt.Errorf("Invalid EnumType[%s] value", s)
 	}
-	st = &value
+	*st = value
 	return nil
 }