A warp yarn tensioning device for a loom, in which the warp yarns are wound about a compensator roller through an arc of approximately 180.degree.. The roller is movable against the action of counteracting springs either by rotation or by translation in the direction of the thus wound substantially parallel warp yarns and is supported about an axis by bearings. The device operates in feeding the shed with yarns from the warp beam and in maintaining a constant yarn tension during loom operation. This is accomplished by supporting the compensator roll to undergo only a small amount of swing or translational movement in order to follow the warp yarn tension variations.