Code completion doesn't work on ui member of GUI project upon creation

If I create a GUI project, go straight to MainWindow's constructor, and try to operate on the ui member, the code completion doesn't work (Creator also fails to locate ui_mainwindow.h as an include).

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui-> // Don't get code completion here.
}

Even if I close the editor and reopen it the problem persists. It goes away when I restart Creator and reload the project.