The invention relates to a compressor assembly (1), particularly a screw compressor for generating compressed air, comprising a compressor housing (2) with an intake opening for admitting the compressed medium. The assembly is equipped with a valve unit (3) comprising a shut-off element (4), which adopts an open position during operation and a closed position when the compressor is switched off. The shut-off element (4) has a plate-type configuration and can be displaced freely in the axial direction between the closed and open positions by means of guide contours (5) configured in the compressor housing (2).