diff --git a/response_writer.go b/response_writer.go
index 9035e6f1..142a7cc5 100644
--- a/response_writer.go
+++ b/response_writer.go
@@ -44,6 +44,9 @@ type ResponseWriter interface {
 
 	// Pusher get the http.Pusher for server push
 	Pusher() http.Pusher
+
+	// Unwrap get the underlying http.ResponseWriter
+	Unwrap() http.ResponseWriter
 }
 
 type responseWriter struct {
diff --git a/response_writer_test.go b/response_writer_test.go
index dfc1d2c6..255559a7 100644
--- a/response_writer_test.go
+++ b/response_writer_test.go
@@ -33,12 +33,23 @@ func init() {
 	SetMode(TestMode)
 }
 
+// test for ResponseWriter.Unwrap
 func TestResponseWriterUnwrap(t *testing.T) {
 	testWriter := httptest.NewRecorder()
 	writer := &responseWriter{ResponseWriter: testWriter}
 	assert.Same(t, testWriter, writer.Unwrap())
 }
 
+func TestResponseWriterUnwrapViaInterface(t *testing.T) {
+	testWriter := httptest.NewRecorder()
+	writer := &responseWriter{}
+	writer.reset(testWriter)
+	var w ResponseWriter = writer
+
+	unwrapped := w.Unwrap()
+	assert.Same(t, testWriter, unwrapped)
+}
+
 func TestResponseWriterReset(t *testing.T) {
 	testWriter := httptest.NewRecorder()
 	writer := &responseWriter{}