diff --git a/src/mainboard/lenovo/x1_carbon_gen1/devicetree.cb b/src/mainboard/lenovo/x1_carbon_gen1/devicetree.cb
index e4204dd..ce74d3f 100644
--- a/src/mainboard/lenovo/x1_carbon_gen1/devicetree.cb
+++ b/src/mainboard/lenovo/x1_carbon_gen1/devicetree.cb
@@ -77,6 +77,9 @@
 			register "c2_latency" = "101"  # c2 not supported
 			register "p_cnt_throttling_supported" = "1"
 
+			register "spi_uvscc" = "0x2005"
+			register "spi_lvscc" = "0x2005"
+
 			device pci 14.0 on
 				subsystemid 0x17aa 0x21f9
 			end # USB 3.0 Controller