diff --git a/src/mainboard/google/reef/variants/baseboard/devicetree.cb b/src/mainboard/google/reef/variants/baseboard/devicetree.cb
index f15260b2db..c83df61f59 100644
--- a/src/mainboard/google/reef/variants/baseboard/devicetree.cb
+++ b/src/mainboard/google/reef/variants/baseboard/devicetree.cb
@@ -12,6 +12,10 @@ chip soc/intel/apollolake
 	register "pcie_rp4_clkreq_pin" = "CLKREQ_DISABLED"
 	register "pcie_rp5_clkreq_pin" = "CLKREQ_DISABLED"
 
+	# GPIO for PERST_0
+	# If the Board has PERST_0 signal, assign the GPIO
+	# If the Board does not have PERST_0, assign GPIO_PRT0_UDEF
+	register "prt0_gpio" = "GPIO_PRT0_UDEF"
 
 	# EMMC TX DATA Delay 1
 	# Refer to EDS-Vol2-22.3.