The present disclosure concerns an assembly for a drug delivery device (1)comprising a housing (3), a first abutment surface (64), a second abutment surface (21), and a detachable member (7) which is detachable from the housing (3) and attachable to the housing (3), wherein the assembly is configured such that, during detachment of the detachable member (7) from the housing (3) for an Nth time, N being a predetermined number, the first abutment surface (64) is brought into abutment with the second abutment surface (21), wherein the assembly is configured such that, when the first abutment surface (64) abuts with the second abutment surface (21), the detachable member (7) is enabled to be reattached to the housing (3) and, afterwards, the detachable member (7) is prevented from being detached from the housing (3).