The observation by Maday in 1974 that the Schmidt-Duffin solution to the optimal fin profile problem was flawed due to neglect of the slant height factor led to a new solution—actually, a demonstration of the ill-posedness of the question—by Snider. The present article proves mathematically that omission of this factor leads inevitably to underestimation of the heat transfer capability of any fin. Additionally, a perturbation scheme for estimating the correction for this effect is derived for configurations with low generalized Biot numbers, and a revised assessment of the performance of the Schmidt fin is presented.