  Many extensions of the Standard Model predict the existence of charged Higgs
bosons. In order to be able to find those particles, an accurate description of
their production is needed. In Monte Carlo simulations of charged Higgs boson
production at hadron colliders, the two tree-level processes gb->H+/-t and
gg->H+/-tb are used. Since those processes overlap in the collinear region of
the phase-space of the outgoing b-quark, care must be taken not to introduce
double-counting if both processes are to be used together. In this talk I
present a method for matching these processes, developed by Johan Rathsman and
myself. The method also allows for investigations of the factorization scale
dependence of the processes and a better understanding of which factorization
scale to choose to get a reliable description of charged Higgs production.
