We show that the claims in the NOTE of Klamt et al. regarding our recent work "Towards the development of theoretically correct liquid activity coefficient models" are quite misleading. Their analysis shows the equivalence of the COSMOSPACE and our model for lattice fluids with short range interactions. For systems with long-range interactions or when a clear choice for the area of segment surface is not possible, the two methods will behave differently. (C) 2009 Elsevier Ltd. All rights reserved.