QStateMachine: adding parallel states to running machine fails

QStateMachine machine;

QState* parallel = new QState(QState::ParallelStates, &machine);
machine.setInitialState(parallel);

QFinalState* final = new QFinalState(&machine);
parallel->addTransition(parallel, SIGNAL(finished()), final);

machine.start();
QCoreApplication::processEvents();

QState* group = new QState(parallel);
QState* s1 = new QState(group);
group->setInitialState(s1);
QFinalState* done = new QFinalState(group);
s1->addTransition(s1, SIGNAL(entered()), done);

QEventLoop loop;
connect(&machine, SIGNAL(finished()), &loop, SLOT(quit()));

machine.start();
loop.exec();