A cap assembly (200) for a drug delivery device is presented. The cap assembly (200) comprises a fixing element (134) with a connection feature (154), an outer part (130) with an opening (164), and an inner part (131) being located inside of the outer part (130), the inner part (131) further comprising a corresponding connection feature (170), wherein a section of the fixing element (134) extends through the opening (164) of the outer part (130), such that the fixing element (134) is connected to the inner part (131) by an interaction of the connection feature (154) and the corresponding connection feature (170).