Seam: required page parameters not working?

[Karsten Wutzke]

Hello,

I've just discovered a required attribute in the pages.xml:

 <page view-id="/competition-list.xhtml">
  <param name="season" value="#{seasonHome.id}" converterId="javax.faces.Integer" validator="#{startYearValidator}" required="true" />
 </page>

However, when manually deleting the parameter from the URL nothing happens, that is the query is still executed, though it returns no elements, which I didn't expect.

What am I doing wrong?

Karsten