An assembly for a drug delivery device (1) is provided comprising a housing (2) having a distal end and a proximal end, a dose button (4) configured to be moved with respect to the housing (2) for setting and delivering a dose of a drug from the device (1), and a blocking member (3). The blocking member (3) is adapted and arranged to be releasably coupled to the housing (2) such that, when the blocking member (3) is coupled to the housing (2), movement of the dose button (4) with respect to the housing (2) is prevented. Furthermore, a drug delivery device is provided.
