deconstructor of QFileSystemWatcher hangs if run after deconstruction of Q(Core)Application

Having a QFileSystemWatcher instance connected to a singleton run by Q_GLOBAL_STATIC(...) and having it only deleted on the singleton's destruction (as QObject child) this QFileSystemWatcher instance will stop the program from exiting and get it stuck in ~QFileSystemWatcher with this backtrace:
(gdb) bt
#0 0x013a0ae0 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1 0x0113c97d in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/libQtCore.so.4
#2 0x0113b712 in QThread::wait(unsigned long) () from /usr/lib/libQtCore.so.4
#3 0x0121a883 in QFileSystemWatcher::~QFileSystemWatcher() () from /usr/lib/libQtCore.so.4
#4 0x01262349 in QObjectPrivate::deleteChildren() () from /usr/lib/libQtCore.so.4
#5 0x0126b1c5 in QObject::~QObject() () from /usr/lib/libQtCore.so.4
#6 0x00136020 in QctSettingsSingleton::~QctSettingsSingleton() () from /home/openist/build.m6.i/qtcontacts-tracker/src/lib/libqtcontacts_extensions_tracker.so.4
#7 0x001352ac in QGlobalStaticDeleter<QctSettingsSingleton>::~QGlobalStaticDeleter (this=0x139b00, __in_chrg=<value optimized out>)
at /targets/maemo6-i486/usr/include/qt4/QtCore/qglobal.h:1820
#8 0x01511f2c in ?? () from /lib/libc.so.6
#9 0x01511f95 in exit () from /lib/libc.so.6
#10 0x014f9a47 in __libc_start_main () from /lib/libc.so.6
#11 0x0805ce31 in _start ()

A workaround is to do
connect(qApp, SIGNAL(aboutToQuit()), myFileSystemWatcher, SLOT(deleteLater()));
but this is nowhere documented and feels strange.