A headrest assembly for a vehicle seat. The headrest assembly includes a support bracket having a first engagement section and a moveable bracket movable between first and second positions. The headrest assembly further includes a pawl defining a cam surface. The pawl has a second engagement section and is pivotable between an engaged position, with the second engagement section engaging the first engagement section, and a disengaged position, with the second engagement section spaced from the first engagement section. The headrest assembly further includes a first tab selectively engaging and guiding the pawl into the engaged position, and a second tab selectively engaging and guiding the pawl into the disengaged position as the moveable bracket moves between the first and second positions. The headrest assembly further includes a biasing member engaging the cam surface to continuously bias the pawl into both of the engaged and disengaged positions.