diff --git a/gcc/m2/Make-lang.in b/gcc/m2/Make-lang.in
index 02754e98c572..480c4fb28a7e 100644
--- a/gcc/m2/Make-lang.in
+++ b/gcc/m2/Make-lang.in
@@ -1477,7 +1477,7 @@ mcflex.c: $(srcdir)/m2/mc/mc.flex
 
 m2/gm2-libs-boot/M2RTS.o: $(srcdir)/m2/gm2-libs/M2RTS.mod $(MCDEPS) $(BUILD-BOOT-H)
 	-test -d $(@D)/$(DEPDIR) || $(mkinstalldirs) $(@D)/$(DEPDIR)
-	$(MC) --suppress-noreturn -o=m2/gm2-libs-boot/M2RTS.c $(srcdir)/m2/gm2-libs/M2RTS.mod
+	$(MC) -o=m2/gm2-libs-boot/M2RTS.c $(srcdir)/m2/gm2-libs/M2RTS.mod
 	$(COMPILER) $(CM2DEP) -c -DIN_GCC $(CFLAGS) $(GM2_PICFLAGS) $(MC_SRC_FLAGS) -I$(srcdir)/m2 -Im2 -I. -Im2/gm2-libs-boot -I$(srcdir)/m2/gm2-libs-ch $(MCINCLUDES) $(INCLUDES) m2/gm2-libs-boot/M2RTS.c -o $@
 	$(POSTCOMPILE)
 
diff --git a/gcc/m2/gm2-libs-min/M2RTS.mod b/gcc/m2/gm2-libs-min/M2RTS.mod
index ae8cbfffbec9..1f04a027f82c 100644
--- a/gcc/m2/gm2-libs-min/M2RTS.mod
+++ b/gcc/m2/gm2-libs-min/M2RTS.mod
@@ -69,6 +69,8 @@ END ExecuteInitialProcedures ;
 
 PROCEDURE HALT ;
 BEGIN
+   LOOP
+   END
 END HALT ;
 
 
diff --git a/gcc/m2/gm2-libs/M2RTS.mod b/gcc/m2/gm2-libs/M2RTS.mod
index 41add830766e..5ea4d17c02c2 100644
--- a/gcc/m2/gm2-libs/M2RTS.mod
+++ b/gcc/m2/gm2-libs/M2RTS.mod
@@ -286,7 +286,7 @@ END ErrorMessageC ;
            to stderr and calls exit (1).
 *)
 
-PROCEDURE HaltC (description, filename, function: ADDRESS; line: CARDINAL) ;
+PROCEDURE HaltC (description, filename, function: ADDRESS; line: CARDINAL) <* noreturn *> ;
 BEGIN
    ErrorMessageC (description, filename, line, function)
 END HaltC ;