An airbag cushion assembly (10, 100) has an airbag cushion (12) and an inflator (20, 120). The airbag cushion has a plurality of inflatable chambers including a primary chamber (11, 111) configured to receive inflation gas and one or more additional chambers (14, 16, 114, 115, 116) for receiving inflation gas from the primary chamber (11, 111). The inflator (20, 120) is in communication with, or open to, the gas inlet of the primary chamber (11, 111). One or more of the additional chambers has one or more one-way gas flow check valves (30, 130) for receiving inflation gases into the chamber and preventing the received gases from back flowing to maintain the one or more additional chambers at full inflation when the airbag cushion is inflated and loaded.