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