How can I remove data type information from my xml in ruby?

I converted ruby hash data to xml. My xml includes key type such as type="integer"

<problemID type="integer">3</problemID>

How can I remove the type information from my xml? such as the line below

<problemID>3</problemID>

Here is my code which generates xml from hash data.

my_xml = my_hash.to_xml(:root => 'problem')

Thanks alot.