Using to_xml with folders in model cause invalid XML

With subfolders in model folders the to_xml method generates invalid XML:

ie:

I have this sctructure:
-models --resources ----post.rb

The class name in post.rb is Resources::Post

The to_xml method generates:

<?xml version="1.0" encoding="UTF-8"?> <resources/posts type="array">
<resources/post>

<description>