  In this talk I report on progress towards the computation of the
next-to-next-to-leading order virtual corrections to Higgs boson pair
production in gluon fusion, in an expansion around the forward-scattering
limit. The results of this computation will provide an estimate of the size and
uncertainty of the three-loop virtual corrections in a comparatively much
larger region of phase space than the results available in the literature,
which are based on an expansion in the limit of a large top quark mass.
