diff --git a/errors.go b/errors.go
index dd4dc75..cf054da 100644
--- a/errors.go
+++ b/errors.go
@@ -59,7 +59,7 @@ type marshalable interface {
 	json.Unmarshaler
 }
 
-type ErrorCodec interface {
+type RPCErrorCodec interface {
 	FromJSONRPCError(JSONRPCError) error
 	ToJSONRPCError() (JSONRPCError, error)
 }
diff --git a/handler.go b/handler.go
index 68cdffc..591a6da 100644
--- a/handler.go
+++ b/handler.go
@@ -284,7 +284,7 @@ func (s *handler) createError(err error) *JSONRPCError {
 	}
 
 	switch m := err.(type) {
-	case ErrorCodec:
+	case RPCErrorCodec:
 		o, err := m.ToJSONRPCError()
 		if err != nil {
 			log.Warnf("Failed to convert error to JSONRPCError: %v", err)
@@ -455,12 +455,12 @@ func (s *handler) handle(ctx context.Context, req request, w func(func(io.Writer
 				Message: err.Error(),
 			}
 
-			if m, ok := err.(ErrorCodec); ok {
-				respErr, err := m.ToJSONRPCError()
+			if m, ok := err.(RPCErrorCodec); ok {
+				rpcErr, err := m.ToJSONRPCError()
 				if err != nil {
 					log.Warnf("Failed to convert error to JSONRPCError: %v", err)
 				} else {
-					resp.Error.Data = respErr.Data
+					respErr.Data = rpcErr.Data
 				}
 			}
 
diff --git a/resp_error_test.go b/resp_error_test.go
index 0e56814..e5b2bec 100644
--- a/resp_error_test.go
+++ b/resp_error_test.go
@@ -35,7 +35,7 @@ func (e *SimpleError) ToJSONRPCError() (JSONRPCError, error) {
 	return JSONRPCError{Message: e.Message}, nil
 }
 
-var _ ErrorCodec = (*SimpleError)(nil)
+var _ RPCErrorCodec = (*SimpleError)(nil)
 
 type DataStringError struct {
 	Message string `json:"message"`
@@ -62,7 +62,7 @@ func (e *DataStringError) ToJSONRPCError() (JSONRPCError, error) {
 	return JSONRPCError{Message: e.Message, Data: e.Data}, nil
 }
 
-var _ ErrorCodec = (*DataStringError)(nil)
+var _ RPCErrorCodec = (*DataStringError)(nil)
 
 type DataComplexError struct {
 	Message      string
@@ -94,7 +94,7 @@ func (e *DataComplexError) ToJSONRPCError() (JSONRPCError, error) {
 	return JSONRPCError{Message: e.Message, Data: data}, nil
 }
 
-var _ ErrorCodec = (*DataComplexError)(nil)
+var _ RPCErrorCodec = (*DataComplexError)(nil)
 
 type MetaError struct {
 	Message string
diff --git a/response.go b/response.go
index 72f92b4..69885bb 100644
--- a/response.go
+++ b/response.go
@@ -52,7 +52,7 @@ func (e *JSONRPCError) Error() string {
 var (
 	_               error = (*JSONRPCError)(nil)
 	marshalableRT         = reflect.TypeOf(new(marshalable)).Elem()
-	unmarshalableRT       = reflect.TypeOf(new(ErrorCodec)).Elem()
+	unmarshalableRT       = reflect.TypeOf(new(RPCErrorCodec)).Elem()
 )
 
 func (e *JSONRPCError) val(errors *Errors) reflect.Value {
@@ -67,7 +67,7 @@ func (e *JSONRPCError) val(errors *Errors) reflect.Value {
 			}
 
 			if v.Type().Implements(unmarshalableRT) {
-				_ = v.Interface().(ErrorCodec).FromJSONRPCError(*e)
+				_ = v.Interface().(RPCErrorCodec).FromJSONRPCError(*e)
 			}
 
 			if len(e.Meta) > 0 && v.Type().Implements(marshalableRT) {