Button onClick function(this) returns window object

Question

I want to create multiple buttons that when clicked pass their object into the function (id for example), but what I get is button passes window object when clicked.

for(var n = 0; n < 10; n++){
    var button = document.createElement("button");
    button.textContent = n;
    document.getElementById("test").appendChild(button);
    button.onclick = () => {
        console.log(this)//returns window object instead of button :(
        console.log(this.id)
    }
}

I searched and found no exact answer to why it could happen or how I can fix this. If I manually add onClick with function(this) it works like a charm