An occupant restraint device includes an inflatable airbag cushion, a tether including a first end connected to the airbag cushion and a second end connected to a tether control mechanism. The tether control mechanism including a tether payout mechanism and a tether length adjustment mechanism. The tether length adjustment mechanism controls a length of tether available for payout by the tether payout mechanism, and the tether payout mechanism is operationally decoupled from the tether length adjustment mechanism.