Abstract: An air seal is provided for restraining the flow of air through a cut-out section of a door which accommodates a door closing mechanism. A pair of nested cover strips individually flexed to a U-shaped configuration is mounted astride the mechanism, the bight of the outer strip resiliently abutting a vertical surface of the cut-out section in air sealing contact. The inner strip, which has greater resistance to flexing than the outer strip, contacts the side sections of the outer strip to stiffen them against flexing as the door is swung about its support. Both strips terminate in a fringed margin to accommodate the vertical rise of the lower boundary surface of the cut-out section as the door swings away from its closed position.