Cannot Create Navtabs

[James]

I'm not sure if the code has changed, but this isn't creating a new navtab for me:

class MyTab_Listener_Navigation
{
public static function navtabs(array &$extraTabs, $selectedTabId)
{
$extratabs['MyTab'] = array(
'title' => 'My Tab',
'href' => XenForo_Link::buildPublicLink('mytab'),
'position' => 'end',
'selected' => ($selectedTabId == 'MyTab')
);
}
}

I have my listener set up to execute MyTab_Listener_Navigation::navtabs.

Can a fresh set of eyes see what I'm doing wrong, if anything?

EDIT: Woops, I noticed I didn't camelcase my extraTabs array. /facepalm