A drug delivery device (1) is provided comprising a housing (2), a cartridge holder (3) which is adapted and arranged for receiving a cartridge (4) for holding a plurality of doses of a drug (5), wherein the cartridge holder (3) is removable from the housing (2) to enable an exchange of the cartridge (4), a piston rod (9) adapted and arranged to be moved from an initial position towards an end position for dispensing a dose of drug (5) from the device (1) and to be moved from the end position back towards the initial position to perform a reset operation of the device (1), and at least one resilient member (20, 25). The at least one resilient member (20, 25) is in direct mechanical contact with the piston rod (9) and the resilient member (20, 25) is adapted and arranged to prevent an unintentional movement of the piston rod (9) towards the initial position due to mechanical cooperation with the piston rod (9).
