autocompleteclose ui is undefined

autocompleteclose ui is undefined

I have

  1. .bind('autocompleteclose', function(event, ui) {
  2.   alert(ui.item.label);
  3.   return true;
  4. })
attached to my autocomplete(), but when the autocomplete closes, I get the error:

ui.item is undefined
alert(ui.item.label);

Is this a bug or is something else going wrong?