A prosthesis liner provided for fitting over a stump of a limb. The prosthesis liner includes a main body having an inner face directed towards the skin of the stump, and an outer face directed away from the stump. The prosthesis liner also includes a proximal access opening and a side wall, which extends from the access opening as far as a closed distal end portion of the liner. At least one sealing lip is arranged on the outer face of the main body and protrudes radially outwards from the main body.