A door frame for a vehicle includes a door frame, a window regulator mounted to the door frame for opening and closing a window pane, and a door lining mounted to the door frame. A plurality of mounting apertures is defined in the door frame, including at least one first mounting aperture for mounting the window regulator and at least one second mounting aperture for mounting the door lining. An isolating aperture is defined in the door frame between the at least one first aperture and the at least one second aperture for isolating the at least one second aperture from the at least one first aperture to thereby reduce lateral forces imparted to the door frame from the window regulator from transferring to the door lining.