Change to Thiago's method: QThread::quit() is *not* thread-safe, so we mustn't call it from outside the QThread that the QThread holds. Unlike other QObjects, this method and some others must not be called from the thread they have affinity to. So add a hack to call it in the auxiliary thread. Do that by connecting a dummy QObject's destroyed() signal to the quit() slot in a DirectConnection, then move the object to the thread. When we call deleteLater(), this will cause the thread's event loop to delete the object, which in turn calls quit() in the actual thread. Reviewed-by: Thiago Macieira