diff --git a/Makefile b/Makefile
index 3d29dc2..99d8dfc 100644
--- a/Makefile
+++ b/Makefile
@@ -28,7 +28,7 @@ CFLAGS += -fno-omit-frame-pointer # More reliable backtraces in GDB
 
 all: kernel.elf
 
-kernel.elf: entry.o start.o lib/string.o lib/proc.o lib/spinlock.o lib/proc.o lib/uart.o lib/panic.o kern/kalloc.o lib/memory.o
+kernel.elf: entry.o start.o lib/string.o lib/proc.o lib/proc.o lib/uart.o lib/panic.o kern/kalloc.o lib/memory.o kern/ispinlock.o lib/spinlock.o
 	@echo LD $@
 	@$(LD) $(LDFLAGS) -o $@ $^
 
@@ -48,3 +48,5 @@ clean:
 	rm -f *.o *.elf *.d lib/*.o lib/*.d
 
 -include *.d
+
+.PHONY: all