diff --git a/codec/json/marshaler.go b/codec/json/marshaler.go
index 9ea03070..85930742 100644
--- a/codec/json/marshaler.go
+++ b/codec/json/marshaler.go
@@ -1,14 +1,18 @@
 package json
 
 import (
+	"bytes"
 	"encoding/json"
 
+	oldjsonpb "github.com/golang/protobuf/jsonpb"
+	oldproto "github.com/golang/protobuf/proto"
 	"github.com/oxtoacart/bpool"
 	jsonpb "google.golang.org/protobuf/encoding/protojson"
 	"google.golang.org/protobuf/proto"
 )
 
 var jsonpbMarshaler = &jsonpb.MarshalOptions{}
+var oldjsonpbMarshaler = &oldjsonpb.Marshaler{}
 
 // create buffer pool with 16 instances each preallocated with 256 bytes
 var bufferPool = bpool.NewSizedBufferPool(16, 256)
@@ -16,19 +20,22 @@ var bufferPool = bpool.NewSizedBufferPool(16, 256)
 type Marshaler struct{}
 
 func (j Marshaler) Marshal(v interface{}) ([]byte, error) {
-	if pb, ok := v.(proto.Message); ok {
-		buf, err := jsonpbMarshaler.Marshal(pb)
-		if err != nil {
-			return nil, err
-		}
-		return buf, nil
+	switch m := v.(type) {
+	case proto.Message:
+		return jsonpbMarshaler.Marshal(m)
+	case oldproto.Message:
+		buf, err := oldjsonpbMarshaler.MarshalToString(m)
+		return []byte(buf), err
 	}
 	return json.Marshal(v)
 }
 
 func (j Marshaler) Unmarshal(d []byte, v interface{}) error {
-	if pb, ok := v.(proto.Message); ok {
-		return jsonpb.Unmarshal(d, pb)
+	switch m := v.(type) {
+	case proto.Message:
+		return jsonpb.Unmarshal(d, m)
+	case oldproto.Message:
+		return oldjsonpb.Unmarshal(bytes.NewReader(d), m)
 	}
 	return json.Unmarshal(d, v)
 }