diff --git a/decode_compile.go b/decode_compile.go
index 8d92f5d..1061e85 100644
--- a/decode_compile.go
+++ b/decode_compile.go
@@ -8,12 +8,8 @@ import (
 
 func (d *Decoder) compileHead(typ *rtype) (decoder, error) {
 	switch {
-	case typ.Implements(unmarshalJSONType):
-		return newUnmarshalJSONDecoder(typ, "", ""), nil
 	case rtype_ptrTo(typ).Implements(unmarshalJSONType):
 		return newUnmarshalJSONDecoder(rtype_ptrTo(typ), "", ""), nil
-	case typ.Implements(unmarshalTextType):
-		return newUnmarshalTextDecoder(typ, "", ""), nil
 	case rtype_ptrTo(typ).Implements(unmarshalTextType):
 		return newUnmarshalTextDecoder(rtype_ptrTo(typ), "", ""), nil
 	}
@@ -22,12 +18,8 @@ func (d *Decoder) compileHead(typ *rtype) (decoder, error) {
 
 func (d *Decoder) compile(typ *rtype, structName, fieldName string) (decoder, error) {
 	switch {
-	case typ.Implements(unmarshalJSONType):
-		return newUnmarshalJSONDecoder(typ, structName, fieldName), nil
 	case rtype_ptrTo(typ).Implements(unmarshalJSONType):
 		return newUnmarshalJSONDecoder(rtype_ptrTo(typ), structName, fieldName), nil
-	case typ.Implements(unmarshalTextType):
-		return newUnmarshalTextDecoder(typ, structName, fieldName), nil
 	case rtype_ptrTo(typ).Implements(unmarshalTextType):
 		return newUnmarshalTextDecoder(rtype_ptrTo(typ), structName, fieldName), nil
 	}
diff --git a/decode_unmarshal_json.go b/decode_unmarshal_json.go
index d951e75..2674a07 100644
--- a/decode_unmarshal_json.go
+++ b/decode_unmarshal_json.go
@@ -38,26 +38,14 @@ func (d *unmarshalJSONDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 	src := s.buf[start:s.cursor]
 	dst := make([]byte, len(src))
 	copy(dst, src)
-	if d.isDoublePointer {
-		newptr := unsafe_New(d.typ.Elem())
-		v := *(*interface{})(unsafe.Pointer(&interfaceHeader{
-			typ: d.typ,
-			ptr: newptr,
-		}))
-		if err := v.(Unmarshaler).UnmarshalJSON(dst); err != nil {
-			d.annotateError(s.cursor, err)
-			return err
-		}
-		*(*unsafe.Pointer)(p) = newptr
-	} else {
-		v := *(*interface{})(unsafe.Pointer(&interfaceHeader{
-			typ: d.typ,
-			ptr: p,
-		}))
-		if err := v.(Unmarshaler).UnmarshalJSON(dst); err != nil {
-			d.annotateError(s.cursor, err)
-			return err
-		}
+
+	v := *(*interface{})(unsafe.Pointer(&interfaceHeader{
+		typ: d.typ,
+		ptr: p,
+	}))
+	if err := v.(Unmarshaler).UnmarshalJSON(dst); err != nil {
+		d.annotateError(s.cursor, err)
+		return err
 	}
 	return nil
 }
diff --git a/decode_unmarshal_text.go b/decode_unmarshal_text.go
index 170f95a..26b28ec 100644
--- a/decode_unmarshal_text.go
+++ b/decode_unmarshal_text.go
@@ -45,16 +45,14 @@ func (d *unmarshalTextDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 	if b, ok := unquoteBytes(dst); ok {
 		dst = b
 	}
-	newptr := unsafe_New(d.typ.Elem())
 	v := *(*interface{})(unsafe.Pointer(&interfaceHeader{
 		typ: d.typ,
-		ptr: newptr,
+		ptr: p,
 	}))
 	if err := v.(encoding.TextUnmarshaler).UnmarshalText(dst); err != nil {
 		d.annotateError(s.cursor, err)
 		return err
 	}
-	*(*unsafe.Pointer)(p) = newptr
 	return nil
 }
 
diff --git a/encode_test.go b/encode_test.go
index 316e3c6..fa3f21f 100644
--- a/encode_test.go
+++ b/encode_test.go
@@ -1298,7 +1298,7 @@ func TestNilMarshal(t *testing.T) {
 		{v: struct{ M string }{"gopher"}, want: `{"M":"gopher"}`},
 		{v: struct{ M json.Marshaler }{}, want: `{"M":null}`},
 		{v: struct{ M json.Marshaler }{(*nilJSONMarshaler)(nil)}, want: `{"M":"0zenil0"}`},
-		{v: struct{ M interface{} }{(*nilJSONMarshaler)(nil)}, want: `{"M":"0zenil0"}`}, // doesn't compatible with encoding/json
+		{v: struct{ M interface{} }{(*nilJSONMarshaler)(nil)}, want: `{"M":null}`},
 		{v: struct{ M encoding.TextMarshaler }{}, want: `{"M":null}`},
 		{v: struct{ M encoding.TextMarshaler }{(*nilTextMarshaler)(nil)}, want: `{"M":"0zenil0"}`},
 		{v: struct{ M interface{} }{(*nilTextMarshaler)(nil)}, want: `{"M":null}`},
diff --git a/encode_vm.go b/encode_vm.go
index 2a83ca0..a3b5768 100644
--- a/encode_vm.go
+++ b/encode_vm.go
@@ -226,35 +226,23 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, code *opcode) error {
 			}
 			vv := rv.Interface()
 			header := (*interfaceHeader)(unsafe.Pointer(&vv))
-			typ := header.typ
-			if typ.Kind() == reflect.Ptr {
-				typ = typ.Elem()
-			}
-			var c *opcode
-			if typ.Kind() == reflect.Map {
-				code, err := e.compileMap(&encodeCompileContext{
-					typ:        typ,
-					root:       code.root,
-					withIndent: e.enabledIndent,
-					indent:     code.indent,
-				}, false)
-				if err != nil {
-					return err
+			if header.typ.Kind() == reflect.Ptr {
+				if rv.Elem().IsNil() {
+					e.encodeNull()
+					e.encodeByte(',')
+					code = code.next
+					break
 				}
-				c = code
-			} else {
-				code, err := e.compile(&encodeCompileContext{
-					typ:        typ,
-					root:       code.root,
-					withIndent: e.enabledIndent,
-					indent:     code.indent,
-				})
-				if err != nil {
-					return err
-				}
-				c = code
 			}
-
+			c, err := e.compileHead(&encodeCompileContext{
+				typ:        header.typ,
+				root:       code.root,
+				withIndent: e.enabledIndent,
+				indent:     code.indent,
+			})
+			if err != nil {
+				return err
+			}
 			beforeLastCode := c.beforeLastCode()
 			lastCode := beforeLastCode.next
 			lastCode.idx = beforeLastCode.idx + uintptrSize