A platform for a bladed wheel having a small hub-tip ratio, suitable for being fabricated out of composite material from a three-dimensionally woven fiber preform, the platform including a bottom wall, a top wall defining an air flow passage, and two side walls extending transversely between the bottom wall and the top wall, wherein the side walls extend longitudinally beyond the upstream end of the bottom wall. The platform further includes a fastener tab that is folded from the upstream end of the bottom wall.