diff --git a/server/grpc/codec.go b/server/grpc/codec.go
index b92b63b4..eb1b09c5 100644
--- a/server/grpc/codec.go
+++ b/server/grpc/codec.go
@@ -10,8 +10,6 @@ import (
 	"github.com/golang/protobuf/proto"
 	"github.com/micro/go-micro/v2/codec"
 	"github.com/micro/go-micro/v2/codec/bytes"
-	"github.com/micro/go-micro/v2/codec/jsonrpc"
-	"github.com/micro/go-micro/v2/codec/protorpc"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/encoding"
 	"google.golang.org/grpc/metadata"
@@ -35,14 +33,6 @@ var (
 		"application/grpc+proto":   protoCodec{},
 		"application/grpc+bytes":   bytesCodec{},
 	}
-
-	defaultRPCCodecs = map[string]codec.NewCodec{
-		"application/json":         jsonrpc.NewCodec,
-		"application/json-rpc":     jsonrpc.NewCodec,
-		"application/protobuf":     protorpc.NewCodec,
-		"application/proto-rpc":    protorpc.NewCodec,
-		"application/octet-stream": protorpc.NewCodec,
-	}
 )
 
 func (w wrapCodec) String() string {
diff --git a/server/grpc/grpc.go b/server/grpc/grpc.go
index 001ea1b5..735b69ff 100644
--- a/server/grpc/grpc.go
+++ b/server/grpc/grpc.go
@@ -16,7 +16,6 @@ import (
 
 	"github.com/golang/protobuf/proto"
 	"github.com/micro/go-micro/v2/broker"
-	"github.com/micro/go-micro/v2/codec"
 	"github.com/micro/go-micro/v2/errors"
 	meta "github.com/micro/go-micro/v2/metadata"
 	"github.com/micro/go-micro/v2/registry"
@@ -510,16 +509,6 @@ func (g *grpcServer) newGRPCCodec(contentType string) (encoding.Codec, error) {
 	return nil, fmt.Errorf("Unsupported Content-Type: %s", contentType)
 }
 
-func (g *grpcServer) newCodec(contentType string) (codec.NewCodec, error) {
-	if cf, ok := g.opts.Codecs[contentType]; ok {
-		return cf, nil
-	}
-	if cf, ok := defaultRPCCodecs[contentType]; ok {
-		return cf, nil
-	}
-	return nil, fmt.Errorf("Unsupported Content-Type: %s", contentType)
-}
-
 func (g *grpcServer) Options() server.Options {
 	g.RLock()
 	opts := g.opts