The invention relates to an apparatus (10) for fastening a gas generator (11) in an oscillatory manner as a vibration damping mass inside an airbag module. A fastening ring (12) provided for fastening the gas generator (11) has at least one elastic section (14) and at least one reinforcement insert (15) for reinforcing the fastening ring (12) and securing the fastening ring (12) to the gas generator. A surface of the reinforcement insert (15) is made at least in part of plastic.