A gatherer stitcher for brochures has a stitching machine, a delivery station that receives brochures step-by-step during operation, a trimming apparatus, and transport components (brochure ejector, trimmer feed) that transport the brochures from the delivery station to the trimming apparatus during operation. Sensors assigned to the stitching machine and the transport components output signals defining their phase position, and a control system processes the signals. One of the transport components (brochure ejector; trimmer feed) is activated in such a way that the brochures assume a correct position in the trimming apparatus at a predetermined phase angle of the stitching machine, without regard to their width. Changeover times in the event of job changes required when the brochure width changes are shortened.