Abstract: A plastic siding panel for forming a weather-resistant facade on an exterior wall of a building, and which is resistant to being dislodged from the building wall by relatively high apparent wind velocities, which are frequently encountered during transportation of a prefabricated building module. The panel comprises a contoured sheet of a plastic material typically having an ornamental facing, a generally flat nailhem strip at an upper end thereof, and an elongate rib located on the nailhem strip. The rib provides additional strength and rigidity which makes the plastic siding panels of the invention significantly more resistant to dislodgement from a building wall, upon exposure to relatively high winds, than conventional plastic siding panels.