diff --git a/src/mainboard/google/fatcat/variants/baseboard/fatcat/devicetree.cb b/src/mainboard/google/fatcat/variants/baseboard/fatcat/devicetree.cb
index f3a0a65ba5..b9dcbbdf64 100644
--- a/src/mainboard/google/fatcat/variants/baseboard/fatcat/devicetree.cb
+++ b/src/mainboard/google/fatcat/variants/baseboard/fatcat/devicetree.cb
@@ -51,6 +51,12 @@ chip soc/intel/pantherlake
 		[PchSerialIoIndexUART2] = PchSerialIoDisabled,
 	}"
 
+	register "serial_io_gspi_mode" = "{
+		[PchSerialIoIndexGSPI0] = PchSerialIoPci,
+		[PchSerialIoIndexGSPI1] = PchSerialIoPci,
+		[PchSerialIoIndexGSPI0A] = PchSerialIoPci,
+	}"
+
 	register "pch_hda_dsp_enable" = "true"
 	register "pch_hda_idisp_link_tmode" = "HDA_TMODE_8T"
 	register "pch_hda_idisp_link_frequency" = "HDA_LINKFREQ_96MHZ"