A cartridge holder (2) which has a distal end and a proximal end comprises a coupling housing portion (14) in which a cartridge can be inserted at least partly. The coupling housing portion (14) is configured to be coupled to a part of a drug delivery device. The cartridge holder (2) further comprises a fixing member (21) which is connected with the coupling housing portion (14). The fixing member (21) is moveable radially inwardly to a position in which the fixing member (21) is suitable for securing the cartridge against distal displacement of the cartridge.