diff --git a/src/soc/intel/apollolake/Makefile.inc b/src/soc/intel/apollolake/Makefile.inc
index a03ac49961..38ed07deb6 100644
--- a/src/soc/intel/apollolake/Makefile.inc
+++ b/src/soc/intel/apollolake/Makefile.inc
@@ -35,6 +35,7 @@ smm-y += pmutil.c
 smm-y += smihandler.c
 smm-y += spi.c
 smm-y += tsc_freq.c
+smm-y += uart_early.c
 
 ramstage-$(CONFIG_HAVE_ACPI_TABLES) += acpi.c
 ramstage-y += cpu.c