Recently, Breiter et al. [Celest. Mech. Dyn. Astron., 2004, 88, 153 161] reported the computation of Hansen coefficients X _k ^{gamma ,m} for non-integer values of gamma. In fact, the Hansen coefficients are closely related to the Laplace b _s ^(m), and generalized Laplace coefficients b _s,r ^(m) [Laskar and Robutel, 1995, Celest. Mech. Dyn. Astron., 62, 193 217] that do not require s,r to be integers. In particular, the coefficients X ₀ ^{gamma ,m} have very simple expressions in terms of the usual Laplace coefficients b _{gamma +2} ^(m), and all their properties derive easily from the known properties of the Laplace coefficients.