diff --git a/boards/mbed_lpc1768/Makefile.include b/boards/mbed_lpc1768/Makefile.include
index 243cfb6ca0..ddc74b030f 100644
--- a/boards/mbed_lpc1768/Makefile.include
+++ b/boards/mbed_lpc1768/Makefile.include
@@ -36,6 +36,7 @@ export ASFLAGS += -ggdb -g3 $(CPU_USAGE) $(FPU_USAGE) -mlittle-endian
 export LINKFLAGS += -g3 -ggdb -std=gnu99 $(CPU_USAGE) $(FPU_USAGE) -mlittle-endian -static -lgcc -mthumb -mthumb-interwork -nostartfiles
 export LINKFLAGS += -T$(LINKERSCRIPT)
 export OFLAGS = -O binary
+export HEXFILE = $(ELFFILE:.elf=.bin)
 export FFLAGS =
 export DEBUGGER_FLAGS =
 export TERMFLAGS += -p "$(PORT)"