diff --git a/examples/standalone/Makefile b/examples/standalone/Makefile
index abe1bf1883483dd947017a7f492853878dcaec9b..f01816f24f4a3851f1c9e1eada5a1fe42b75e430 100644
--- a/examples/standalone/Makefile
+++ b/examples/standalone/Makefile
@@ -62,11 +62,11 @@ quiet_cmd_link_elf = LD      $@
 $(ELF): $(obj)/%: $(obj)/%.o $(LIB) FORCE
 	$(call if_changed,link_elf)
 
-$(obj)/%.srec: OBJCOPYFLAGS := -O srec
+$(obj)/%.srec: OBJCOPYFLAGS += -O srec
 $(obj)/%.srec: $(obj)/% FORCE
 	$(call if_changed,objcopy)
 
-$(obj)/%.bin: OBJCOPYFLAGS := -O binary
+$(obj)/%.bin: OBJCOPYFLAGS += -O binary
 $(obj)/%.bin: $(obj)/% FORCE
 	$(call if_changed,objcopy)