The Taylor expansion procedure introduced by Apagyi and Scheid (1983 J. Phys. G: Nucl. Phys. 9 73) for localization of nonlocal potentials has been re-examined and improved to include third-order corrections. The method has been applied to the real part of the nonlocal potential describing n-⁴⁰ Ca scattering. Comparison with exact results and investigation of phase shifts show that inclusion of second-order correction terms may be sufficient to obtain a quick assessment of the local space effect of the underlying nonlocal potential.