A method for securing a cartridge (4) in a cartridge holder (3) is provided, the method comprising the steps of inserting the cartridge (4) into the cartridge holder (3), the cartridge holder (3) having a proximal end and a distal end, axially displacing the cartridge (4) in a proximal direction with respect to the cartridge holder (3) from a distal initial position to a proximal end position and securing the cartridge (4) in the end position against displacement in the distal direction with respect to the cartridge holder (3). An assembly for a drug delivery device (1) is provided comprising a cartridge (4), an adjusting member (12, 25, 28, 34) and a cartridge holder (3). The cartridge holder (3) has a distal end and a proximal end. The adjusting member (12, 25, 28, 34) is secured to the cartridge holder (3). The adjusting member (12, 25, 28, 34) holds a distal portion of the cartridge (4) at a distance with respect to a distal portion of the cartridge holder (3).