The tensor susceptibility of an antiferromagnetic with uniaxial anisotropy has been calculated using several modifications of the Bloch damping term. The axial component of the susceptibility is particularly simple and is readily tested by the Kronig‐Kramers dispersion relations as modified by Gourary. It is found that, of the damping terms considered, only one which includes relaxation to the instantaneous equilibrium magnetizations will pass this test.