The new code in kdc_util.c request->kdc_options &= ~(TGS_OPTIONS_HANDLED); Actually causes clears the kdc_options field of all handled options, which (in most cases) zeros the field. This is probably not intended... To properly disable unrecognized flags, I think you need to do something like this: badflags = (request->kdc_options & ~(TGS_OPTIONS_HANDLED)); request->kdc_options &= ~badflags; -Wyllys -- Wyllys Ingersoll