  We consider leading $O(m/M)$ nuclear recoil corrections to the hyperfine
splitting in light atomic systems. Due to the singularity of hyperfine
interactions, the electromagnetic form factors of the nucleus have to be
introduced as a function of the four-momentum square, which goes beyond the
Hamiltonian description of the system. We present a compact formula for
$O(Z\,\alpha)$ recoil corrections and indicate the importance, especially for
light atoms, of a more realistic description of the nuclear structure effects.
