In at least one embodiment of the present invention, a device for pretensioning a seatbelt is provided. The device comprises a spindle for receiving a portion of the seatbelt. A retractor frame that has a weakened portion is supported by the spindle for rotational movement within the retractor frame. A pretensioner is operatively connected to the spindle for rotating the spindle to tighten the seatbelt. The pretensioner includes pretensioner balls. The pretensioner is configured to drive the pretensioner balls toward a ball collection area adjacent to the weakened portion. The weakened portion is deformed by the pretensioner balls to increase the size of the ball collection area.