diff --git a/ChangeLog b/ChangeLog
index 7cd2c37..b17c2b8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2013-11-26  Niibe Yutaka  <gniibe@fsij.org>
+
+	* rules.mk (OUTFILES) [ENABLE_OUTPUT_HEX]: Add hex generation.
+
 2013-11-21  Niibe Yutaka  <gniibe@fsij.org>
 
 	* example-cdc/usb_stm32f103.c, example-cdc/usb_lld.h: Update from
diff --git a/rules.mk b/rules.mk
index b493a1d..86f641c 100644
--- a/rules.mk
+++ b/rules.mk
@@ -10,6 +10,10 @@ INCDIR += $(CHOPSTX)
 
 BUILDDIR = build
 OUTFILES = $(BUILDDIR)/$(PROJECT).elf $(BUILDDIR)/$(PROJECT).bin
+ifneq ($(ENABLE_OUTPUT_HEX),)
+OUTFILES += $(BUILDDIR)/$(PROJECT).hex
+endif
+
 
 OPT += -ffunction-sections -fdata-sections -fno-common
 
@@ -49,6 +53,9 @@ $(OBJS) : $(BUILDDIR)/%.o : %.c Makefile
 %.bin: %.elf $(LDSCRIPT)
 	$(OBJCOPY) -O binary $< $@
 
+%.hex: %.elf $(LDSCRIPT)
+	$(OBJCOPY) -O ihex $< $@
+
 clean:
 	-rm -f -r .dep $(BUILDDIR)