A method is presented for treating singularities which occur in solutions of parabolic partial differential equations due to sharp corners in the boundary. The method is essentially an extension of the method due to Motz (1946) for solving elliptic problems and approximates to the analytical form of the singularity in terms of neighbouring function values at each time step. It is used in conjunction with the simple explicit finite-difference scheme and subsequently the overall method is explicit. The accuracy of solutions of a typical problem is discussed.