A vehicle safety system for helping to protect an occupant of a vehicle seat includes a seatbelt extensible around the occupant to help restrain the occupant in the vehicle seat. The seatbelt includes a lap belt configured to extend across the occupant at the hips. An airbag is secured to the lap belt and configured to inflate and deploy upward from the lap belt to a deployed position in front of the occupant. The system is configured to adjust the deployed position of the airbag in response to the position of the occupant.