The steady axisymmetric flow of a thin fluid layer on a rotating disk is studied. It is shown that within the restrictions of lubrication theory the Coriolis force is of the same magnitude as inertia and therefore negligible at leading order. In this paper we extend the standard lubrication approximation to provide a correction to the classical relation between film height and flux. The correction terms, caused by the Coriolis force and inertia terms, lead to slightly higher predictions for the film height. This is in keeping with experimental results. It is also shown that recent work incorrectly concludes that the Coriolis force enters the leading order force balance. (c) 2005 Elsevier B.V. All rights reserved.