An annular backing plate for a diffuser in a centrifugal compressor comprises an inner diameter and an outer diameter disposed radially opposite the inner diameter. The backing plate also includes a first surface extending between the inner diameter and the outer diameter of the backing plate. A step is formed on the first surface proximate the inner diameter, wherein the step shifts a portion of the first surface encompassed by the step axially aft relative a portion of the first surface not encompassed by the step.