diff --git a/cpu/lh7a40x/Makefile b/cpu/lh7a40x/Makefile
index b9ae76e..1b3f58a 100644
--- a/cpu/lh7a40x/Makefile
+++ b/cpu/lh7a40x/Makefile
@@ -26,7 +26,7 @@
 LIB	= $(obj)lib$(CPU).a
 
 START	= start.o
-COBJS	= cpu.o speed.o serial.o timer.o
+COBJS	= cpu.o speed.o timer.o
 
 SRCS	:= $(START:.o=.S) $(SOBJS:.o=.S) $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(SOBJS) $(COBJS))