The present invention relates to an assembly for a drug delivery device comprising a dispensing container (60) and a reservoir container (70) for holding a fluid medicinal product, wherein the dispensing container (60) and the reservoir container (70) are connected to one another and are in fluid communication, and wherein the dispensing container (60) is squeezable for dispensing a dose of the fluid medicinal product from the dispensing container (60), the dispensing container (60) being refillable with the fluid medicinal product from the reservoir container (70).