A medicament delivery device is shown for the administration of one or more drug agents. The device comprises a medicament cartridge retainer for holding a medicament cartridge. A dispense interface can be attached to an attachment of the device for facilitating fluidic communication from the device. Further, an interface sensor is configured to provide an output indicative of whether the dispense interface is attached to the attachment. The device also comprises a piston rod for driving a bung of the medicament cartridge, and a drive train for advancing the piston rod to the bung. A controller is configured to control the drive train to advance the piston rod towards the bung when the output of the interface sensor indicates that the dispense interface is not on the attachment. The controller is further configured to disable advancement of the piston rod when the output of the interface sensor indicates that the dispense interface is at least partially on the attachment.
