Described is a medicament delivery device (1), comprising a piston rod (11), and a container carrier (7) for retaining a medicament container, such as a syringe (8), within the body (2). At least one longitudinal rib (2.2) associated with the piston rod (11) is arranged to engage the carrier (7). At least one of the carrier (7) and the at least one rib (2.2) comprises a resilient material adapted to be deformed by the engagement between the carrier (7) and the at least one rib (2.2).