The present disclosure relates to a medicament delivery device (1) for injection of a medicament. The medicament delivery device (1) comprising a housing (3) having a distal end opening and a proximal end opening a needle guard (9) extending from the proximal end opening and moveable relative tothe housing (3) from an extended position to a retracted position in which the needle guard (9) is biased towards the extended position. The device (1) further comprises an activation member (5) extending from the distal end opening and movable relative to the housing (3) from an initial position to a final position final position locking means arranged to restrict movement of the activation member (5) relative to the housing (3) when the activation member (5) is in the final position, and needle guard locking means arranged to interact with the needle guard (9) such that movement of the needle guard (9) from the extended position to the retracted position is restricted when the activation member (5) is in the final position. The present disclosure also relates to a method of assembling a medicament delivery device (1).
