A magazine for a fastener tool comprising a first guideway for heads of fastener elements of a first type, the first guideway extending in a direction (A) and being configured to position tips of the fastener elements of first type near a front edge extending substantially parallel to the direction (A); and comprising a second guideway for heads of fastener elements of a second type, the fastener elements of the first type having a different length from that of the fastener elements of second type, the second guideway being configured to position tips of the fastener elements of second type near the front edge. The magazine further comprises a poka-yoke configured to prevent inserting of the fastener elements of second type in the first guideway.