A climate-control system includes a first compressor, a second compressor, a first heat exchanger, a second heat exchanger, and a third heat exchanger. The first compressor includes a first inlet and a first outlet. The second compressor is in fluid communication with the first compressor and includes a second inlet (e.g., a suction inlet), a third inlet (e.g., a vapor-injection inlet), a second compression mechanism, and a second outlet. The second and third inlets are fluidly coupled with the second compression mechanism. The second compression mechanism receives working fluid from the first compressor through the third inlet and discharges working fluid through the second outlet of the second compressor. The first and second compressors are in fluid communication with the first, second, and third heat exchangers.