A guide rail arrangement for an extensible cover. The guide rail arrangement has a main extension direction (D) and comprises a guide rail and a guide member. The guide rail extends in the main extension direction and is adapted to guide the cover during pull-out thereof. The guide member is displaceable in relation to the guide rail, e.g. by sliding or rotation. The guide member is configured to form an extension of the guide rail in the main extension direction, when in an operational position in relation to the guide rail. The present disclosure further relates to a kit comprising the guide rail arrangement and a belt, to a vehicle and to a method of pulling out the extensible cover.