Bootstrap Typeahead updater not being run

Question

I am trying to have a custom updater function with Bootstrap 2.3.2. The updater function doesn't seem to be called for some reason.

HTML

<input id="options_select" type="text" class="options"/><br/>
<textarea id="options_all" rows="5"></textarea><br/>                    

SCRIPT

$(document).ready(function() {      

    var source = [
        { id: 1, name: 'Courses' },
        { id: 2, name: 'Finance' },
        { id: 3, name: 'Housing' },
        { id: 4, name: 'Jobs' },
        { id: 5, name: 'Lifestyle' },           
        { id: 6, name: 'Travel' },          
        { id: 7, name: 'Miscellaneous' },];

    $('#options_select').typeahead({

        source: source,
        updater: function(item) {
            alert('hi');
            return item;
        }                
    }); 
});

The typeahead is working fine, but why isn't the alert showing up?