A restraint system includes an A pillar, a dash extending in a cross-vehicle direction from the A pillar, a door extending in a vehicle-rearward direction from the A pillar, and an airbag mounted to the A pillar and inflatable to an inflated position. The airbag includes a side chamber and a front chamber. The side chamber is elongated along the door when the airbag is in the inflated position, and the front chamber is elongated along the dash when the airbag is in the inflated position.