A harvesting machine includes a draper header with a header frame, a crop-cutting assembly attached to the header frame along the length thereof and configured to cut a crop, and a draper assembly positioned behind the crop-cutter assembly and operable to receive severed crop material from the crop-cutter assembly and convey the material laterally. The draper assembly includes a draper belt with a crop-retaining rib to retain severed crop material on the draper belt and to restrict movement of the crop material back to the crop-cutting assembly. At least one belt guard is attached to and disposed along the crop-cutting assembly.