An assembly for a drug delivery device includes a housing, a rotation member, a drive member and at least one correction member. In a delivery mode, the drive member and the rotation member are coupled such that the drive member follows rotational movement of the rotation member in a first rotational direction. In a correction mode, the rotation member and the drive member are decoupled such that the rotation member is rotatable in the first rotational direction with respect to the drive member. For switching from the delivery mode into the correction mode, the correction member is moveable with respect to the housing, wherein the assembly is configured such that movement of the correction member with respect to the housing is converted into a relative movement between the drive member and the rotation member for decoupling the drive member and the rotation member.