diff --git a/src/mainboard/lenovo/t420s/devicetree.cb b/src/mainboard/lenovo/t420s/devicetree.cb
index 92c9085..b5576b2 100644
--- a/src/mainboard/lenovo/t420s/devicetree.cb
+++ b/src/mainboard/lenovo/t420s/devicetree.cb
@@ -18,9 +18,9 @@
 	device domain 0 on
 		subsystemid 0x17aa 0x21d2 inherit
 
-		device pci 00.0 on end # host bridge
-		device pci 01.0 on end # NVIDIA Corporation GF119M [NVS 4200M]
-		device pci 02.0 on
+		device ref host_bridge on end # host bridge
+		device ref peg10 on end # NVIDIA Copcie_rporation GF119M [NVS 4200M]
+		device ref igd on
 			subsystemid 0x17aa 0x21d3
 		end # Integrated Graphics Controller
 
@@ -51,28 +51,28 @@
 			register "spi_uvscc" = "0x2005"
 			register "spi_lvscc" = "0x2005"
 
-			device pci 16.0 on  end # Management Engine Interface 1
-			device pci 16.1 off end # Management Engine Interface 2
-			device pci 16.2 off end # Management Engine IDE-R
-			device pci 16.3 off end # Management Engine KT
-			device pci 19.0 on
+			device ref mei1 on  end # Management Engine Interface 1
+			device ref mei2 off end # Management Engine Interface 2
+			device ref me_ide_r off end # Management Engine IDE-R
+			device ref me_kt off end # Management Engine KT
+			device ref gbe on
 				subsystemid 0x17aa 0x21ce
 			end # Intel Gigabit Ethernet
-			device pci 1a.0 on end # USB Enhanced Host Controller #2
-			device pci 1b.0 on end # High Definition Audio Controller
-			device pci 1c.0 off end # PCIe Port #1
-			device pci 1c.1 on end # PCIe Port #2 Integrated Wireless LAN
-			device pci 1c.2 off end # PCIe Port #3
-			device pci 1c.3 on
+			device ref ehci2 on end # USB Enhanced Host Controller #2
+			device ref hda on end # High Definition Audio Controller
+			device ref pcie_rp1 off end # PCIe Port #1
+			device ref pcie_rp2 on end # PCIe Port #2 Integrated Wireless LAN
+			device ref pcie_rp3 off end # PCIe Port #3
+			device ref pcie_rp4 on
 				smbios_slot_desc "7" "3" "ExpressCard Slot" "8"
 			end # PCIe Port #4 ExpressCard
-			device pci 1c.4 on end # PCIe Port #5 NEC Corporation uPD720200A USB 3.0 Host Controller
-			device pci 1c.5 off end # PCIe Port #6 Intel Gigabit Ethernet PHY (not PCIe)
-			device pci 1c.6 off end # PCIe Port #7
-			device pci 1c.7 off end # PCIe Port #8
-			device pci 1d.0 on end # USB Enhanced Host Controller #1
-			device pci 1e.0 off end # PCI bridge
-			device pci 1f.0 on
+			device ref pcie_rp5 on end # PCIe Port #5 NEC Corporation uPD720200A USB 3.0 Host Controller
+			device ref pcie_rp6 off end # PCIe Port #6 Intel Gigabit Ethernet PHY (not PCIe)
+			device ref pcie_rp7 off end # PCIe Port #7
+			device ref pcie_rp8 off end # PCIe Port #8
+			device ref ehci1 on end # USB Enhanced Host Controller #1
+			device ref pci_bridge off end # PCI bridge
+			device ref lpc on
 				chip ec/lenovo/pmh7
 					device pnp ff.1 on end # dummy
 					register "backlight_enable" = "0x01"
@@ -134,8 +134,8 @@
 					register "has_thinker1" = "1"
 				end
 			end # LPC Controller
-			device pci 1f.2 on end # 6 port SATA AHCI Controller
-			device pci 1f.3 on
+			device ref sata1 on end # 6 port SATA AHCI Controller
+			device ref smbus on
 				# eeprom, 8 virtual devices, same chip
 				chip drivers/i2c/at24rf08c
 					device i2c 54 on end
@@ -148,8 +148,8 @@
 					device i2c 5f on end
 				end
 			end # SMBus Controller
-			device pci 1f.5 off end # SATA Controller 2
-			device pci 1f.6 on end # Thermal
+			device ref sata2 off end # SATA Controller 2
+			device ref thermal on end # Thermal
 		end
 	end
 end