QApplication::beep() doesn't work on xcb

#include <QApplication>
#include <QTimer>
#include <QWidget>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QTimer timer;
    QObject::connect(&timer, &QTimer::timeout, [](){
        qDebug("beep");
        QApplication::beep();
    });
    timer.start(1000);

    QWidget widget;
    widget.setGeometry(120,120,240,240);
    widget.show();
    return QApplication::exec();
}

xcb_flush(connection);