diff --git a/sysdeps/m68k/Makefile b/sysdeps/m68k/Makefile
index 09f3b4355e..886744365c 100644
--- a/sysdeps/m68k/Makefile
+++ b/sysdeps/m68k/Makefile
@@ -2,10 +2,10 @@
 # way to choose a sysdep file based on MIT vs Motorola syntax.
 # No existing m68k ports use Motorola syntax.
 
-crypt := crypt.sun3	# Use uf-crypt/crypt.sun3.S.
+crypt := crypt.sun3	# Use crypt/crypt.sun3.S.
 
 # Disgusting magic to get `#'s into the asm code.
-$(objpfx)%.o: %.S
-	$(CC) $(CPPFLAGS) -E $< \
-	| sed 's/(@@@Hash-Here@@@)/#/g' | $(AS) $(ASFLAGS) -o $@
-.S-rule := t
+define compile-command.S
+$(CC) $(CPPFLAGS) -E $< \
+| sed 's/(@@@Hash-Here@@@)/#/g' | $(AS) $(ASFLAGS) -o $@
+endef