  State-of-the-art predictions for the mass of the lightest MSSM Higgs boson
usually involve the resummation of higher-order logarithmic contributions
obtained within an effective-field-theory (EFT) approach, often combined with a
fixed-order calculation into a hybrid result. For the phenomenologically
interesting case of a significant hierarchy between the gluino mass and the
masses of the scalar top quarks the predictions suffer from large theoretical
uncertainties related to non-decoupling power-enhanced gluino contributions in
the EFT results employing the $\overline{\text{DR}}$ renormalisation scheme. We
demonstrate that the theoretical predictions in the heavy gluino region are
vastly improved by the introduction of a suitable renormalisation scheme for
the EFT calculation. It is shown that within this scheme a recently proposed
resummation of large gluino contributions is absorbed into the model
parameters, resulting in reliable and numerically stable predictions in the
heavy-gluino gluino region. We also discuss the integration of the results into
the public code FeynHiggs.
