An autoinjector comprising a body (1) and an actuator sleeve (10) that is movable relative to 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； one of said actuator sleeve (10) and of said body (1) including a flexible tab (110) that is adapted to deform laterally relative to said actuator sleeve (10) and/or relative to said body (1) when said actuator sleeve (10) is moved from its first projecting position to its actuated position, then from its actuated position to return to its second projecting position, the other of said actuator sleeve (10) and of said body (1) including an initial zone (102) that co-operates with said flexible tab (110) in said first projecting position, an intermediate zone (105) that co-operates with said flexible tab (110) in said actuated position, and a final reception zone (106) that co-operates with said flexible tab (110) in said second projecting position, said final reception zone (106) being offset, at least laterally, from said initial zone (102), a deformable axial wall (1020) being adapted to deform elastically so as to allow said flexible tab (110) to pass from said initial zone (102) to said intermediate zone (105), said deformable axial wall (1020), in its non-deformed position, then being adapted to guide said flexible tab from said intermediate zone (105) to said final reception zone (106).
