btn class disabled invalid

[ycxwoo]

<button class="btn disabled">**The mouse click is still valid**</button>

[bopoda]

really.
But it is a full ace code.
you can try:

<button class="btn disabled" disabled="disabled">Click</button>

Or using js:

$('body').on('click', 'a.disabled', function(event) {
    event.preventDefault();
});