Abstract: An arrangement for attaching a falling post on a base structure, the post being rotatably movable between a standing and a recumbent position. The arrangement includes a stand, wherein the post is attached pivotally to the stand by a pin. The stand includes at least one groove arranged laterally in respect to the post, and the post has at least one projection extending in a lateral direction from the post. The at least one groove is arranged with respect to the at least one projection such that when the stand is in the standing position, the at least one projection lies in the at least one groove, and thereby locks the post in the standing position. The at least one projection is attached to the post such that it may move with respect to the stand in a longitudinal direction of the post.