We derive modified Lüscher equation that enables one to extract scattering phase shifts from the lattice energy levels even in the
presence of a long-range force. The method avoids large partial-wave mixing which is a priori expected in the presence of such force, and is applicable in the region of the left-hand cut. More details can be found in the recent publication R.Bubna, H.~W.Hammer, F.Müller, J.-Y.Pang, A.Rusetsky and J.-J.Wu, JHEP 05 (2024) 168, arXiv:2402.12985 [hep-lat].