A combine harvester comprising a feeder and a detachable header, the feeder comprising a carrier structure (20,21) for lifting up the header from the ground or from a trailer, wherein: • the carrier structure comprises a pair of securing pins oriented transversely relative to the forward direction of the combine, and an actuator located between the pins and configured to move the pins towards or away from each other while the pins maintain their transverse orientation, • immovably attached to each securing pin is at least one stop protruding outward from the pin in the forward direction, the stops having a front surface that is sloped relative to the respective pins, • the header comprises a positioning aid for each of the stops, and a pair of slots configured to receive the ends of the securing pins, and wherein: • the positioning aids are placed relative to the sloped surfaces of the respective stops in such a manner that after the header is lifted up by the carrier structure (20,21), the positioning aids are configured to roll or glide down the sloped surfaces under the influence of the actuator moving the securing pins away from each other, thereby enabling a gradual approach of the header towards a securing position relative to the carrier structure (20,21), • the slots on the header are placed so that when the header reaches said securing position, the pins are aligned with the slots, so that the continued actuation of the outward movement of the pins by the actuator drives the ends of the securing pins into the slots, thereby securing the header to the carrier structure (20,21). • the carrier structure comprises a pair of securing pins oriented transversely relative to the forward direction of the combine, and an actuator located between the pins and configured to move the pins towards or away from each other while the pins maintain their transverse orientation, • immovably attached to each securing pin is at least one stop protruding outward from the pin in the forward direction, the stops having a front surface that is sloped relative to the respective pins, • the header comprises a positioning aid for each of the stops, and a pair of slots configured to receive the ends of the securing pins, and wherein: • the positioning aids are placed relative to the sloped surfaces of the respective stops in such a manner that after the header is lifted up by the carrier structure (20,21), the positioning aids are configured to roll or glide down the sloped surfaces under the influence of the actuator moving the securing pins away from each other, thereby enabling a gradual approach of the header towards a securing position relative to the carrier structure (20,21), • the slots on the header are placed so that when the header reaches said securing position, the pins are aligned with the slots, so that the continued actuation of the outward movement of the pins by the actuator drives the ends of the securing pins into the slots, thereby securing the header to the carrier structure (20,21). • the positioning aids are placed relative to the sloped surfaces of the respective stops in such a manner that after the header is lifted up by the carrier structure (20,21), the positioning aids are configured to roll or glide down the sloped surfaces under the influence of the actuator moving the securing pins away from each other, thereby enabling a gradual approach of the header towards a securing position relative to the carrier structure (20,21), • the slots on the header are placed so that when the header reaches said securing position, the pins are aligned with the slots, so that the continued actuation of the outward movement of the pins by the actuator drives the ends of the securing pins into the slots, thereby securing the header to the carrier structure (20,21).