In the paper [Phys. B 550 (2018) 367-375], Alekberov, Isayev, Mekhtiyeva and Fabian have performed very erroneous calculation on diameter of voids responsible for the first sharp diffraction peak (FSDP) in neutron diffraction patterns of As2Se3-based glasses. The authors used wrong relation for the FSDP position taken from entirely speculative assertion presented by Kavetskyy in [Semicond. Phys. Quantum Electron. Optoelectron. 16 (2013) 136-139], assuming unreasonable equivalence between chemistry of chalcogenide glasses and typical polymers. In this communication, the deep reason for this incorrectness was disclosed, and alternative variant to estimate diameters of interstitial voids responsible for the FSDP in As2Se3-based glasses was presented.