The present invention is directed to a drug delivery device comprising a cartridge with a movable bung, a drive mechanism including a bearing for driving the bung in a distal direction for delivering a medicament and a piston rod for actuating the bearing. An electric conductor for transmitting an electrical signal is provided, wherein the electric conductor is configured such that a conductive connection is established or interrupted when the piston rod contacts the bearing or when the bearing contacts the bung. The invention is further directed to a method for detecting the contact between the drive mechanism and the movable bung.
