The invention relates to a master cylinder fitting (100) for a hydraulic actuating element, having a housing (107) comprising an equalisation chamber (170) with an inner chamber (172) and a cylinder (140), the master cylinder fitting (100) also comprising a piston (150) guided in the cylinder (140). The cylinder (140) and the compensation chamber (170) are connected in at least one position of the piston via a connection channel (171), at least one overflow channel (173) being arranged at least at the mouth of the connection channel (171) in the cylinder wall.