An autoinjector comprising a body (1) that is adapted to receive a reservoir (S), said reservoir (S) containing fluid and including a piston (P) and a needle (A), such as a pre-filled syringe, said autoinjector further comprising an actuator sleeve (10) that is movable relative to said body (1) between projecting positions in which said actuator sleeve (10) projects out from said body (1) at least in part, and an actuated position in which said actuator sleeve (10) is moved axially into said body (1), said actuator sleeve (10) being in a first projecting position before actuation of the autoinjector, and in a second projecting position after actuation of the autoinjector; said actuator sleeve (10) being urged towards said projecting positions by a spring (9), said autoinjector including a removable cap (20) that is fastened to said body (1) before the autoinjector is used, said removable cap (20), when it is fastened to said body (1), moving said actuator sleeve (10) axially relative to said first projecting position through a distance (d) into said body (1), against the force of said spring (9), such that when said removable cap (20) is removed from said body (1), said spring (9) returns said into said first projecting position.