Call random function Javascript, but not twice the same function

I use a function that randomly selects another function, which works. But sometimes it runs the same function twice or even more often in a row.

Is there a way to prevend this?

My current code:

window.setInterval(function(){
        var arr = [func1, func2, func3],
        rand = Math.floor(Math.random() * arr.length),
        randomFunction = arr[rand];
        randomFunction();
}, 5000);

Pretty simple so far. But how do I prevent func1 (for example) to run twice in a row