diff --git a/Makefile b/Makefile
index 8d57c1e..e472cf8 100644
--- a/Makefile
+++ b/Makefile
@@ -1,31 +1,31 @@
 export PYTHONPATH := $(PWD)/tools/nrfutil:$(PWD)/tools/intelhex:$(PYTHONPATH)
 
-JOBS = -j $(shell nproc)
-
 all : bootloader micropython
 
+BOARD=$(error Please set BOARD=)
+
 clean :
 	rm -rf \
-		bootloader/_build-nitrogen_nrf52832 \
+		bootloader/_build-$(BOARD)_nrf52832 \
 		micropython/mpy-cross/build \
-		micropython/ports/nrf/build-dsd6-s132
+		micropython/ports/nrf/build-$(BOARD)-s132
 
 submodules :
 	git submodule update --init --recursive
 
 bootloader:
-	make -C bootloader/ BOARD=nitrogen_nrf52832 $(JOBS) all genhex
+	$(MAKE) -C bootloader/ BOARD=$(BOARD)_nrf52832 all genhex
 	python3 tools/hexmerge.py \
+		bootloader/_build-$(BOARD)_nrf52832/$(BOARD)_nrf52832_bootloader-*-nosd.hex \
 		bootloader/lib/softdevice/s132_nrf52_6.1.1/s132_nrf52_6.1.1_softdevice.hex \
-		bootloader/_build-nitrogen_nrf52832/nitrogen_nrf52832_bootloader-*-nosd.hex \
 		-o bootloader.hex
 
 micropython:
-	make -C micropython/mpy-cross $(JOBS)
-	make -C micropython/ports/nrf BOARD=dsd6 SD=s132 $(JOBS)
+	$(MAKE) -C micropython/mpy-cross
+	$(MAKE) -C micropython/ports/nrf BOARD=$(BOARD) SD=s132
 	python3 -m nordicsemi dfu genpkg \
 		--dev-type 0x0052 \
-		--application micropython/ports/nrf/build-dsd6-s132/firmware.hex \
+		--application micropython/ports/nrf/build-$(BOARD)-s132/firmware.hex \
 		micropython.zip
 	
 dfu: