An improved method for the treatment of the long range corrections in molecular simulations of inhomogeneous systems with planar interfaces is presented. To evaluate the quality of this approach, Monte Carlo simulations of the Lennard-Jones fluid are performed in the temperature range T* is an element of < 0.7, 1.25 >. The attention is focused especially on the values of the surface tension, which represents a property significantly sensitive to the truncation of the intermolecular interactions. When the presented approach is employed, the values of coexisting densities and surface tensions obtained with the cutoff distance R-c = 2.5 sigma are within experimental errors identical with those obtained for cutoff distance R-c = 5.5 sigma.