An auto-injector comprises a chassis to contain a syringe with a, needle and a stopper, a needle shroud slideable within the chassis and adapted to rest on the skin of a patient, a plunger adapted to translate the stopper to expel medicament, a coupling shroud slideable within the chassis and releasably coupled to the plunger and a drive means, the drive means driving the coupling shroud proximally from a first position Proximal movement of the coupling shroud translates the syringe exposing the needle, depresses the plunger to expel medicament and advances the needle shroud to a safe position to surround the needle. The needle shroud arranged to prevent decoupling of plunger and coupling shroud when the needle shroud is in a retracted position, whereas the needle shroud is arranged to allow decoupling of plunger and coupling shroud when the needle shroud is moved towards the safe position.