diff --git a/arch/x86/cpu/slimbootloader/Makefile b/arch/x86/cpu/slimbootloader/Makefile
index 9e6822a..aac9fa3 100644
--- a/arch/x86/cpu/slimbootloader/Makefile
+++ b/arch/x86/cpu/slimbootloader/Makefile
@@ -2,4 +2,4 @@
 #
 # Copyright (C) 2019 Intel Corporation <www.intel.com>
 
-obj-y += car.o slimbootloader.o sdram.o
+obj-y += car.o slimbootloader.o sdram.o serial.o