diff --git a/Makefile b/Makefile
index 2a2aade..118ccb9 100644
--- a/Makefile
+++ b/Makefile
@@ -17,6 +17,7 @@ CFLAGS += -march=rv64gc -mabi=lp64
 CFLAGS += -ffreestanding -fno-common -nostdlib -mno-relax
 
 CFLAGS += -I.
+CFLAGS += -Ilib
 
 CFLAGS += -fno-stack-protector # Prevents code that needs libc / runtime support
 CFLAGS += -MD # Generate header dependency files (.d)
@@ -26,7 +27,7 @@ CFLAGS += -fno-omit-frame-pointer # More reliable backtraces in GDB
 
 all: kernel.elf
 
-kernel.elf: entry.o start.o
+kernel.elf: entry.o start.o lib/string.o
 	@echo LD $@
 	@$(LD) $(LDFLAGS) -o $@ $^
 
@@ -39,10 +40,10 @@ kernel.elf: entry.o start.o
 	@$(AS) $(ASFLAGS) -o $@ $<
 
 qemu: kernel.elf
-	@echo QEMU $@
-	@qemu-system-riscv64 -machine virt -bios none -nographic -kernel kernel.elf
+	@echo QEMU $<
+	@qemu-system-riscv64 -machine virt -bios none -nographic -m 128M -smp 4 -kernel kernel.elf
 
 clean:
-	rm -f *.o *.elf *.d
+	rm -f *.o *.elf *.d lib/*.o lib/*.d
 
 -include *.d