The present invention relates to a medicament delivery device comprising a housing (10) adapted to receive a medicament container (24) an actuation member (48) movable from a first position to a second position, such that the medicament is allowed to be expelled through the delivery member (28)an interlock member (46) movable between a locking position, and a releasing position, the device having an indicator to show that it has been used provided by the actuation member (48) being retained in its second position. The invention is characterised in that the actuation member comprises at least one latching projection (58) and the drive mechanism comprises corresponding latching surfaces (64) against which the latching projections (58) latch when the actuation member (48) is in its second position.