Clicking Mac title bar in other window doesn't close popup

#include <QApplication>
#include <QWidget>
#include <QLineEdit>

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

	QWidget widgetWindow;
	widgetWindow.setFixedSize(200,100);
	QLineEdit* edit = new QLineEdit(&widgetWindow);
	widgetWindow.setWindowTitle("Window 1");
	widgetWindow.show();

	QWidget widgetWindow2;
	widgetWindow2.setBaseSize(QSize(200,100));
	widgetWindow2.setWindowTitle("Window 2");
	widgetWindow2.show();

	return a.exec();
}