InvalidStateError - Kendo UI Upload

I keep getting this weird bug where when I try to set my Authorization header, I keep getting 'InvalidStateError'. Here is my code:

$("#files").kendoUpload({
                        async: {
                            saveUrl: myApiUrl + "/" + id,
                            autoUpload: true
                        },
                        upload: function(e) {
                            var xhr = e.XMLHttpRequest;
                            if (xhr) {
                                xhr.addEventListener("readystatechange", function onReady(e) {
                                    if (xhr.readyState === 1 /* OPENED */) {
                                            xhr.setRequestHeader("Authorization", "Bearer " + accessToken);
                                    }
                                });
                            }
                        }
                    });

It turns out that IE for some reason fires the readystatechange twice for readyState==1. I dont know why but it does. Its the second time that it calls it that make it throw the error. So here is my solution:

After the first time it is called, I just remove the listener.

$("#files").kendoUpload({
                        async: {
                            saveUrl: myApiUrl + "/" + id,
                            autoUpload: true
                        },
                        upload: function(e) {
                            var xhr = e.XMLHttpRequest;
                            if (xhr) {
                                xhr.addEventListener("readystatechange", function onReady(e) {
                                    if (xhr.readyState === 1 /* OPENED */) {
                                        xhr.setRequestHeader("Authorization", "Bearer " + accessToken);
                                        xhr.removeEventListener("readystatechange", onReady);
                                    }
                                });
                            }
                        }
                    });