According to the invention, an auto-injector (1) for administering a dose of a liquid medicament (M) comprises- a substantially cylindrical housing (2) arranged to contain a pre-filled syringe (5) filled with the medicament (M),- a needle shroud (3) slibably arranged with respect to the housing (2) and adapted to rest on the skin of a patient receiving an injection,- a releasable drive means (8) arranged within the housing (2) that is capable of, upon release, translating the needle shroud (3) in a proximal direction (P) towards a safe position (PS) and- a rotating collar (14) rotatably arranged within the housing (2). The needle shroud (3) in the safe position (PS) surrounds the injection needle (12) after the injection has been carried out. The rotating collar (14) engages the needle shroud (3) in a manner that forces the rotating collar (14) to rotate within the housing (2) when the needle shroud (3) is translated in the proximal direction (P).