[jQuery] Anyone seen "toggleClass is not defined"

[jQuery] Anyone seen "toggleClass is not defined"


I keep receiving an error with this bit of code on click
$(document).ready(function() {
$('div.example').click( function() {
    $(this).toggleClass("activated");
});
});
It works, but I keep receiving an error stating that
"toggleClass is not defined"
How would I define this?