  We consider the full genuine next-to-leading order SUSY-QCD corrections to
the charged Higgs decays into quarks supplemented by the NNLO corrections to
the effective top and bottom Yukawa couplings. The NNLO corrections to the
effective top Yukawa coupling are a new ingredient of our analysis. We arrive
at an approximate NNLO prediction for MSSM charged Higgs decays after including
the N$^4$LO QCD corrections for large charged Higgs masses. The residual
uncertainties are in the percent range or below, depending on the particular
MSSM scenario.
