The present invention relates to a sealing wafer (1) adapted to be arranged in a stoma receiving hole (5) of a base plate (2) comprising an attachment platform extending from an outer edge adapted to be attached to the base plate towards an inner edge defining a through-going hole (17) for receiving a stoma, the sealing wafer further comprising at least a first urging part extending transversely from the proximal surface facing towards the user during use of the attachment platform and wherein the first urging part is resilient in the direction transverse to the proximal surface. This provides a sealing wafer which is particularly suitable for use with a stoma around which the skin has an uneven curvature, such as a retracted stoma wherein the stoma has pulled back resulting in a crater-like area.