diff --git a/protocol/codec.go b/protocol/codec.go
index b47133c..cad843a 100644
--- a/protocol/codec.go
+++ b/protocol/codec.go
@@ -10,7 +10,7 @@ import (
 
 // Codec creates a CodecRequest to process each request.
 type Codec interface {
-	NewRequest(rc io.Reader) CodecRequest
+	NewRequest(rc io.Reader) (CodecRequest, error)
 }
 
 // CodecRequest decodes a request and encodes a response using a specific
diff --git a/protocol/json/server.go b/protocol/json/server.go
index 32c8546..cd80a00 100644
--- a/protocol/json/server.go
+++ b/protocol/json/server.go
@@ -72,7 +72,7 @@ type Codec struct {
 }
 
 // NewRequest returns a CodecRequest.
-func (c *Codec) NewRequest(r io.Reader) protocol.CodecRequest {
+func (c *Codec) NewRequest(r io.Reader) (protocol.CodecRequest, error) {
 	return newCodecRequest(r, c.encSel.Select(r))
 }
 
@@ -81,12 +81,13 @@ func (c *Codec) NewRequest(r io.Reader) protocol.CodecRequest {
 // ----------------------------------------------------------------------------
 
 // newCodecRequest returns a new CodecRequest.
-func newCodecRequest(r io.Reader, encoder encode.Encoder) protocol.CodecRequest {
+func newCodecRequest(r io.Reader, encoder encode.Encoder) (protocol.CodecRequest, error) {
 	// Decode the request body and check if RPC method is valid.
 	req := new(serverRequest)
 	err := json.NewDecoder(r).Decode(req)
 	if err == io.ErrUnexpectedEOF || err == io.EOF {
 		log.Printf("NewRequest err: %v", err)
+		return nil, err
 	}
 	if err != nil {
 		err = &Error{
@@ -103,7 +104,7 @@ func newCodecRequest(r io.Reader, encoder encode.Encoder) protocol.CodecRequest
 		}
 	}
 
-	return &CodecRequest{request: req, err: err, encoder: encoder}
+	return &CodecRequest{request: req, err: err, encoder: encoder}, nil
 }
 
 // CodecRequest decodes and encodes a single request.
diff --git a/registry.go b/registry.go
index 555df63..25ce4b4 100644
--- a/registry.go
+++ b/registry.go
@@ -101,7 +101,10 @@ func (rr *rpcRegistry) Invoke(contentType string, r io.Reader, w io.Writer, befo
 
 	log.Print("codec.NewRequest")
 	// Create a new codec request.
-	codecReq := codec.NewRequest(r)
+	codecReq, errNew := codec.NewRequest(r)
+	if nil != errNew {
+		return errNew
+	}
 	// Get service method to be called.
 	log.Printf("codecReq.Method: %v", codecReq)
 	method, errMethod := codecReq.Method()