diff --git a/code/game/objects/transfer_valve.dm b/code/game/objects/transfer_valve.dm
index 29f0713922b..3404d4b6498 100644
--- a/code/game/objects/transfer_valve.dm
+++ b/code/game/objects/transfer_valve.dm
@@ -127,11 +127,13 @@
 	icon_state = "valve"
 
 	if(tank_one)
-		src.underlays += "[tank_one.icon_state]"
+		overlays += "[tank_one.icon_state]"
 	if(tank_two)
 		var/icon/J = new(icon, icon_state = "[tank_two.icon_state]")
 		J.Shift(WEST, 13)
-		src.underlays += J
+		underlays += J
+	if(attached_device)
+		overlays += "device"
 
 /obj/item/device/transfer_valve/proc/merge_gases()
 	tank_two.air_contents.volume += tank_one.air_contents.volume
diff --git a/icons/obj/assemblies.dmi b/icons/obj/assemblies.dmi
index 73c63b703cc..80b959a1157 100644
Binary files a/icons/obj/assemblies.dmi and b/icons/obj/assemblies.dmi differ