An assembly for a drug delivery device comprises a housing, at least one stop feature and at least one blocking member. For setting a dose of a drug, the stop feature is configured to be rotated in a dose setting direction with respect to the blocking member and with respect to the housing. For delivering the set dose of the drug, the blocking member is configured to be axially displaced with respect to the stop feature away from an axial starting position and towards an axial interaction position. When the blocking member is in the axial starting position, the blocking member is axially offset from the stop feature and, when the blocking member is in the axial interaction position, the blocking member is configured to mechanically cooperate with the stop feature such that rotation of the stop feature in the dose setting direction with respect to the housing is prevented.