A locking device for a motor vehicle bonnet, wherein the locking device comprises a locking mechanism with a rotary latch and a pawl for locking the rotary latch in a main latching position. Wherein the locking device also comprises a catch hook which can define an opening movement of a lock retainer in a secure position which is between an intended closed position and an intended open position after opening the locking mechanism, wherein the catch hook comprises a load dependent barrier, and the locking device is designed such that a movement of the lock retainer in the direction of the barrier is defined by the barrier dependent on the load in the intended locked position, such that the lock retainer only goes in further than the intended closed position when there is an overload. A further developed locking device with pedestrian protection can also be provided.