diff --git a/decode_interface.go b/decode_interface.go
index a445848..2138f68 100644
--- a/decode_interface.go
+++ b/decode_interface.go
@@ -1,6 +1,7 @@
 package json
 
 import (
+	"encoding"
 	"reflect"
 	"unsafe"
 )
@@ -39,11 +40,56 @@ var (
 	)
 )
 
+func decodeWithUnmarshaler(s *stream, unmarshaler Unmarshaler) error {
+	start := s.cursor
+	if err := s.skipValue(); err != nil {
+		return err
+	}
+	src := s.buf[start:s.cursor]
+	dst := make([]byte, len(src))
+	copy(dst, src)
+
+	if err := unmarshaler.UnmarshalJSON(dst); err != nil {
+		return err
+	}
+	return nil
+}
+
+func decodeWithTextUnmarshaler(s *stream, unmarshaler encoding.TextUnmarshaler) error {
+	start := s.cursor
+	if err := s.skipValue(); err != nil {
+		return err
+	}
+	src := s.buf[start:s.cursor]
+	dst := make([]byte, len(src))
+	copy(dst, src)
+
+	if err := unmarshaler.UnmarshalText(dst); err != nil {
+		return err
+	}
+	return nil
+}
+
 func (d *interfaceDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 	s.skipWhiteSpace()
 	for {
 		switch s.char() {
 		case '{':
+			runtimeInterfaceValue := *(*interface{})(unsafe.Pointer(&interfaceHeader{
+				typ: d.typ,
+				ptr: p,
+			}))
+			rv := reflect.ValueOf(runtimeInterfaceValue)
+			if rv.NumMethod() > 0 && rv.CanInterface() {
+				if u, ok := rv.Interface().(Unmarshaler); ok {
+					return decodeWithUnmarshaler(s, u)
+				}
+				if u, ok := rv.Interface().(encoding.TextUnmarshaler); ok {
+					return decodeWithTextUnmarshaler(s, u)
+				}
+				return nil
+			}
+			// empty interface
 			var v map[string]interface{}
 			ptr := unsafe.Pointer(&v)
 			if err := newMapDecoder(
diff --git a/decode_unmarshal_json.go b/decode_unmarshal_json.go
index 7383738..f1095aa 100644
--- a/decode_unmarshal_json.go
+++ b/decode_unmarshal_json.go
@@ -57,11 +57,14 @@ func (d *unmarshalJSONDecoder) decode(buf []byte, cursor int64, p unsafe.Pointer
 		return 0, err
 	}
 	src := buf[start:end]
+	dst := make([]byte, len(src))
+	copy(dst, src)
+
 	v := *(*interface{})(unsafe.Pointer(&interfaceHeader{
 		typ: d.typ,
 		ptr: p,
 	}))
-	if err := v.(Unmarshaler).UnmarshalJSON(src); err != nil {
+	if err := v.(Unmarshaler).UnmarshalJSON(dst); err != nil {
 		d.annotateError(cursor, err)
 		return 0, err
 	}
diff --git a/encode_vm.go b/encode_vm.go
index 01f3fa0..9d783c6 100644
--- a/encode_vm.go
+++ b/encode_vm.go
@@ -267,6 +267,12 @@ func (e *Encoder) run(ctx *encodeRuntimeContext, b []byte, code *opcode) ([]byte
 			code = code.next
 		case opMarshalJSON:
 			ptr := load(ctxptr, code.idx)
+			if ptr == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.next
+				break
+			}
 			v := e.ptrToInterface(code, ptr)
 			bb, err := v.(Marshaler).MarshalJSON()
 			if err != nil {
diff --git a/encode_vm_escaped.go b/encode_vm_escaped.go
index 0345338..416d1eb 100644
--- a/encode_vm_escaped.go
+++ b/encode_vm_escaped.go
@@ -229,6 +229,12 @@ func (e *Encoder) runEscaped(ctx *encodeRuntimeContext, b []byte, code *opcode)
 			code = code.next
 		case opMarshalJSON:
 			ptr := load(ctxptr, code.idx)
+			if ptr == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.next
+				break
+			}
 			v := e.ptrToInterface(code, ptr)
 			bb, err := v.(Marshaler).MarshalJSON()
 			if err != nil {
diff --git a/encode_vm_escaped_indent.go b/encode_vm_escaped_indent.go
index 785c0a2..5adf19e 100644
--- a/encode_vm_escaped_indent.go
+++ b/encode_vm_escaped_indent.go
@@ -242,6 +242,12 @@ func (e *Encoder) runEscapedIndent(ctx *encodeRuntimeContext, b []byte, code *op
 			code = code.next
 		case opMarshalJSON:
 			ptr := load(ctxptr, code.idx)
+			if ptr == 0 {
+				b = encodeNull(b)
+				b = encodeIndentComma(b)
+				code = code.next
+				break
+			}
 			v := e.ptrToInterface(code, ptr)
 			bb, err := v.(Marshaler).MarshalJSON()
 			if err != nil {
diff --git a/encode_vm_indent.go b/encode_vm_indent.go
index 3507a46..ad9c30e 100644
--- a/encode_vm_indent.go
+++ b/encode_vm_indent.go
@@ -242,6 +242,12 @@ func (e *Encoder) runIndent(ctx *encodeRuntimeContext, b []byte, code *opcode) (
 			code = code.next
 		case opMarshalJSON:
 			ptr := load(ctxptr, code.idx)
+			if ptr == 0 {
+				b = encodeNull(b)
+				b = encodeIndentComma(b)
+				code = code.next
+				break
+			}
 			v := e.ptrToInterface(code, ptr)
 			bb, err := v.(Marshaler).MarshalJSON()
 			if err != nil {