diff --git a/src/soc/amd/stoneyridge/Makefile.inc b/src/soc/amd/stoneyridge/Makefile.inc
index e93a961602..930b7653b9 100644
--- a/src/soc/amd/stoneyridge/Makefile.inc
+++ b/src/soc/amd/stoneyridge/Makefile.inc
@@ -93,6 +93,7 @@ ramstage-y += tsc_freq.c
 smm-y += smihandler.c
 smm-y += smi_util.c
 smm-y += tsc_freq.c
+smm-$(CONFIG_DEBUG_SMI) += uart.c
 
 CPPFLAGS_common += -I$(src)/soc/amd/stoneyridge
 CPPFLAGS_common += -I$(src)/soc/amd/stoneyridge/include