diff --git a/configs/demo9s12ne64/ostest/Make.defs b/configs/demo9s12ne64/ostest/Make.defs
index cdbfda2b355..9135f1e3fe7 100755
--- a/configs/demo9s12ne64/ostest/Make.defs
+++ b/configs/demo9s12ne64/ostest/Make.defs
@@ -46,10 +46,14 @@ ifeq ($(CONFIG_HCS12_NONBANKED),y)
   ARCHCPUFLAGS = -m9s12x -mshort -mnolong-calls
   LDSCRIPT = ld.script.nonbanked
 else
-  ARCHCPUFLAGS = -m9x12x -mshort -mlong-calls
+  ARCHCPUFLAGS = -m9s12x -mshort -mlong-calls
   LDSCRIPT = ld.script.banked
 endif
 
+ifneq ($(CONFIG_HCS12_MSOFTREGS),0)
+  ARCHCPUFLAGS += -msoft-reg-count=$(CONFIG_HCS12_MSOFTREGS)
+endif
+
 ifeq ($(WINTOOL),y)
   # Windows-native toolchains
   DIRLINK = $(TOPDIR)/tools/winlink.sh