QT_REQUIRE_VERSION causes a warning

#include <QApplication>
#include <QMessageBox> // Why is QT_REQUIRE_VERSION found here instead 
                       // of QtGlobal as documented?
#include <QtGlobal>

int main(int argc, char *argv[]) {
	QT_REQUIRE_VERSION(argc, argv, "4.5.0")
	QApplication app(argc, argv);
	return app.exec();
}

g++ -c -pipe -march=native -fomit-frame-pointer -O3 -pipe -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -I. -o main.o main.cpp