Custom Taxonomy and Users

Hi,
I’m registering taxonomies to the user model. Everything works fine, except if I do this:

register_taxonomy(
		'departement',
		array( 'user' ),
		array(
			'public' => true,
			'labels' => array(
				'name' => __( 'Département' ),
				'singular_name' => __( 'Département' )
			),
		)
	);

The taxonomy doesn’t show up under the user menu. If I add ‘post’ to the object_type array it shows up under the the Posts menu. Is it an expected behavior? If so, how em I supposed to manage the taxonomy?

Thank you