diff --git a/Makefile b/Makefile
index fd29efe..827d435 100644
--- a/Makefile
+++ b/Makefile
@@ -5,6 +5,12 @@ CC=$(PREFIX)gcc
 AS=$(PREFIX)as
 OBJCOPY=$(PREFIX)objcopy
 
+ARCH_FLAGS=-mthumb -mcpu=cortex-m4 -mfloat-abi=hard
+CFLAGS=-Og -g -Wall -std=c99 -Ilib/libopencm3/include -DSTM32F4
+LDFLAGS=--static -nostartfiles -Llib/libopencm3/lib
+LDLIBS=-lopencm3_stm32f4
+LDSCRIPT=-Tnucleo-f411re.ld
+
 VPATH=src
 
 .SECONDARY:
@@ -29,10 +35,10 @@ flash: $(NAME).bin
 all: libopencm3 $(NAME).bin
 
 %.o: %.c
-	$(CC) -Og -g -Wall -std=c99 -mthumb -mcpu=cortex-m4 -mfloat-abi=hard -Ilib/libopencm3/include -DSTM32F4 -c $< -o $@
+	$(CC) $(CFLAGS) $(ARCH_FLAGS) -c $< -o $@
 
 %.elf: %.o
-	$(CC) --static -nostartfiles -Tnucleo-f411re.ld -mthumb -mcpu=cortex-m4 -mfloat-abi=hard -Llib/libopencm3/lib $< -lopencm3_stm32f4 -o $@
+	$(CC) $(LDFLAGS) $(LDSCRIPT) $(ARCH_FLAGS) $< $(LDLIBS) -o $@
 
 %.bin: %.elf
 	$(OBJCOPY) $< -O binary $@