A belt-roller arrangement with a deflecting roller and an endless flexible belt and a method for guiding such a belt over such a roller are disclosed. The roller body of the roller includes two deformable roller body segments and a rigid roller body segment part which is—in an axial direction—positioned between these two deformable segments. The belt is entirely guided over the central rigid segment part and at least partially over both deformable segments. The belt run is automatically corrected.