diff --git a/default.go b/default.go
index 0e9364a..2ff74a2 100644
--- a/default.go
+++ b/default.go
@@ -9,6 +9,14 @@ import (
 
 type DefaultError uint32
 
+type DefaultErrorHandler struct {
+	DefaultError
+}
+
+func (*DefaultErrorHandler) ErrorResponse(errorResponse ErrorResponse) ErrorResponse {
+	return DefaultErrorHandler{errorResponse.(DefaultError)}
+}
+
 const (
 	DefaultOk                    DefaultError = http.StatusOK
 	DefaultErrorNotImplemented   DefaultError = http.StatusNotImplemented
@@ -58,6 +66,7 @@ func (e DefaultError) BodyBytes() (body []byte) {
 type DefaultRequestBuilder struct {
 	requestBuilder RequestBuilder
 	prototype      PrototypeRequestBuilder
+	errorHandler   ErrorHandler
 	allowedMethods *[]string
 	header         struct {
 		*Header
@@ -73,7 +82,10 @@ type DefaultRequestBuilder struct {
 	}
 }
 
-func NewDefaultRequestBuilder(rb RequestBuilder, rbp PrototypeRequestBuilder, am *[]string, h *Header, hf header, v *Values, vf values, b *Body, bf body) DefaultRequestBuilder {
+func NewDefaultRequestBuilder(rb RequestBuilder, rbp PrototypeRequestBuilder, eh ErrorHandler, am *[]string, h *Header, hf header, v *Values, vf values, b *Body, bf body) DefaultRequestBuilder {
+	if eh == nil {
+		eh = &DefaultErrorHandler{}
+	}
 	if am == nil {
 		amd := make([]string, 0)
 		am = &amd
@@ -99,6 +111,7 @@ func NewDefaultRequestBuilder(rb RequestBuilder, rbp PrototypeRequestBuilder, am
 	return DefaultRequestBuilder{
 		requestBuilder: rb,
 		prototype:      rbp,
+		errorHandler:   eh,
 		allowedMethods: am,
 		header: struct {
 			*Header
@@ -136,7 +149,7 @@ func (rb *DefaultRequestBuilder) Allowed(method string) (errRes ErrorResponse) {
 		}
 	}
 	if !ok {
-		return DefaultErrorMethodNotAllowed
+		return rb.errorHandler.ErrorResponse(DefaultErrorMethodNotAllowed)
 	}
 	return DefaultOk
 }
@@ -144,23 +157,23 @@ func (rb *DefaultRequestBuilder) Allowed(method string) (errRes ErrorResponse) {
 func (rb *DefaultRequestBuilder) Header(header Header) (errRes ErrorResponse) {
 	err := rb.header.Header.Parse(header)
 	if err != nil {
-		return DefaultErrorBadRequest
+		return rb.errorHandler.ErrorResponse(DefaultErrorBadRequest)
 	}
-	return DefaultOk
+	return rb.errorHandler.ErrorResponse(DefaultOk)
 }
 
 func (rb *DefaultRequestBuilder) ReadBody(body io.ReadCloser) (errRes ErrorResponse) {
 	defer body.Close()
 	json.NewDecoder(body).Decode(rb.body.fields)
-	return DefaultOk
+	return rb.errorHandler.ErrorResponse(DefaultOk)
 }
 
 func (rb *DefaultRequestBuilder) Values(values Values) (errRes ErrorResponse) {
 	err := rb.values.Values.Parse(values)
 	if err != nil {
-		return DefaultErrorBadRequest
+		return rb.errorHandler.ErrorResponse(DefaultErrorBadRequest)
 	}
-	return DefaultOk
+	return rb.errorHandler.ErrorResponse(DefaultOk)
 }
 
 type DefaultResponse struct {
diff --git a/prototype.go b/prototype.go
index 3692ce3..9cdc559 100644
--- a/prototype.go
+++ b/prototype.go
@@ -32,6 +32,11 @@ type ErrorResponse interface {
 	Error() (out string)
 }
 
+type ErrorHandler interface {
+	ErrorResponse
+	ErrorResponse(errorResponse ErrorResponse) ErrorResponse
+}
+
 type Prototype struct {
 	PrototypeRequestBuilder
 	PrototypeResponse