diff --git a/xml/openbmc_intf.xml b/xml/openbmc_intf.xml
index e86a484..791fc48 100644
--- a/xml/openbmc_intf.xml
+++ b/xml/openbmc_intf.xml
@@ -8,6 +8,7 @@
 	<interface name="org.openbmc.Hwmon">
 		<property name="poll_interval" type="i" access="read"/>
 		<property name="sysfs_path" type="s" access="read"/>
+		<property name="scale" type="i" access="read"/>
 	</interface>
 	<interface name="org.openbmc.Fan">
 		<method name="setCoolingZone">