provided is a medicament delivery device that is reliable , safe and intuitive to use and at the same time is easy to use when handling . this is achieved by a medicament delivery device comprising a tubular housing having a proximal end and an opposite distal end , an actuator member being coaxially arranged at the distal end of the tubular housing and movably arranged , in relation to the tubular housing and a cap being releasably connected to the proximal end of the tubular housing wherein the medicament device further comprises a longitudinal actuator interlocking member movably arranged within the tubular housing and interactively connected to both the actuator member and to the cap for controlling movement of the actuator member . thus the cap acts as a device enabler , i . e . it is impossible to actuate the medicament delivery device until the cap has been removed .