Disclosed herein may be a compressor. The compressor may include: a casing; a compression unit configured to suck refrigerant from a suction space of the casing, compress the sucked refrigerant, and discharge the compressed refrigerant to a discharge space of the casing; an oil recovery passage configured to recover oil separated from refrigerant in the discharge space to the suction space; and a reducer inserted into the oil recovery passage to reduce a pressure of oil passing through the oil recovery passage. The reducer may include a deformation preventing unit configured to prevent the reducer from being damaged when the reducer is inserted into the oil recovery passage. Therefore, the reducer may be prevented from being damaged when the reducer is inserted into the oil recovery passage. The costs required to prevent the reducer from being damaged, check the conditions of the reducer, and repair reducer may be reduced.