diff --git a/render/render_test.go b/render/render_test.go
index a56102e63f..20cd2089c7 100755
--- a/render/render_test.go
+++ b/render/render_test.go
@@ -280,10 +280,12 @@ func TestRenderProtoBuf(t *testing.T) {
 	(ProtoBuf{data}).WriteContentType(w)
 	protoData, err := proto.Marshal(data)
 	assert.NoError(t, err)
-	(ProtoBuf{data}).WriteContentType(w)
-	assert.Equal(t, "application/x-protobuf", w.Header().Get("Content-Type"))
 
+	err = (ProtoBuf{data}).Render(w)
+
+	assert.NoError(t, err)
 	assert.Equal(t, string(protoData[:]), w.Body.String())
+	assert.Equal(t, "application/x-protobuf", w.Header().Get("Content-Type"))
 }
 
 func TestRenderXML(t *testing.T) {