An agricultural harvesting machine embodying a forage harvester includes a comminution assembly with a drum equipped with a plurality of knives. The drum is set into rotation opposite a stationary shear bar in order to comminute crop fed in a region of a cutting gap formed by knives and the shear bar during the harvesting operation. A device controls a rotational speed (n) of the drum at least during a maintenance procedure of the comminution assembly, depending on a property of the drum.
