diff --git a/src/soc/intel/skylake/Kconfig b/src/soc/intel/skylake/Kconfig
index 38613e1..3657f6d 100644
--- a/src/soc/intel/skylake/Kconfig
+++ b/src/soc/intel/skylake/Kconfig
@@ -35,6 +35,7 @@
 	select PCIEXP_ASPM
 	select PCIEXP_COMMON_CLOCK
 	select PCIEXP_CLK_PM
+	select PCIEXP_L1_SUB_STATE
 	select REG_SCRIPT
 	select RELOCATABLE_RAMSTAGE
 	select RELOCATABLE_MODULES