An annular circulation chamber is arranged in an interior of a compressor housing, which circulation chamber radially surrounds a main flow duct and extends from an intake region to an encircling circulation opening in a region of rotor blades of the compressor wheel. Between the circulation openings, the circulation chamber is delimited from the main flow duct by an annular contoured wall. The contoured wall is connected to the inner compressor housing by plural struts which are spaced apart from one another to different extents in the circumferential direction. As a result of the irregular distribution of the struts in the circumferential direction, generation of undesired vibration excitations can be reduced and/or eliminated.