Before upgrading to new Qt 5.3.0 framework, one of my apps, which has a full screen overlaying QWidget with the size of the entire desktop main screen, had the entire screen covered, this is, even the MacOSX top menu bar was covered by it. The window was frameless and also set to always stay on top. This worked just fine in Qt 5.2.1. When I upgraded and recompiled using Qt 5.3.0, the window is now rendered exactly with the same size as before but the top menu bar is no longer beneath it, ruining the entire full screen overlay effect I had before. Has the “always on top” behavior changed in any way on MacOSX? I’ve noticed that on Windows it remains consistent, so it must be a MacOSX specific issue. Is there a new flag I need to set on to accomplish this same effect? It seems no matter what flags I fiddle with or how many times I call raise() on that widget, the top menu MacOSX bar will always be on top of my widget.