A fastening system having a supporting strip, to which is fastened, outside the housing of the rotary feeder, a seal designed to seal the blade of the rotor in relation to the housing. The mounted unit of supporting strip and seal is inserted into a groove devised in the blade. This installation unit is then secured to the blade by means of securing screws. The seal can be made from a hard seal, especially steel, or a soft seal, especially rubberized textile, attached on the outside by a locating strip.