The components of the void reactivity effect in the RBMK lattice are obtained using multigroup multidimensional lattice codes. The relative magnitudes of the reactivity change due to changes, on voiding, in neutron absorption and in neutron moderation are compared for several lattice configurations that include either absorber rods or followers of various materials. This has led to the identification of the mechanism that makes the void coefficient dependent on the number of absorber rods in the core. In line with these results, it is shown that replacing the graphite in the follower with nonmoderating materials reduces the void coefficient dependence on the number of absorber rods and is an economic method that may have potential in the void coefficient reduction program.