An attachment for a chainsaw has a lock strip aligned with and near the bottom edge of the chain bar. A plurality of substantially C-shaped stop members engage non-circular indentations formed in the lock strip with one leg and the opposite side of the chain bar with the other leg. The substantially C-shaped stop members are large enough to go around the chain without touching the chain and to block brush and small limbs from being dragged by the chain into the housing. A tightening screw is associated with each of the plurality of substantially C-shaped stop members for holding the C-shaped stop member in a tight relationship with both the lock strip and the chain bar.