The present invention relates to a cartridge holder for a drug delivery device comprising: a distal portion for receiving a cartridge filled with a medicament to be dispensed by the drug delivery device, wherein the distal portion comprises a mount for a piercing assembly, a proximal portion adapted to at least partially receive a drive mechanism having a piston rod to become operably engaged with a piston of the cartridge for expelling a dose of the medicament from the cartridge, wherein the drive mechanism comprises at least first fixing means corresponding with fixing means of the drive mechanism for directly interconnecting cartridge holder and drive mechanism.
