A multi-part cap assembly (120, 200) for a drug delivery device (1) is provided, the cap assembly comprising: a first cap component (131), and a second cap component (130), wherein the first cap component is assembled to the second cap component, wherein one of the first cap component and the second cap component is provided with a guide track (401) and the other one of the first cap component and the second cap component is provided with a guide feature (403), wherein the guide track and the guide feature are arranged to cooperate to form an axial guiding interface between the first cap component and the second cap component, and wherein the axial guiding interface is configured such that relative rotational movement between the first cap component and the second cap component is restricted or prevented. Furthermore, a kit for assembling a cap and a method for assembling a cap are provided as well as a drug delivery device.
