diff --git a/meta-witherspoon/recipes-phosphor/settings/phosphor-settings-read-settings-mrw-native.bbappend b/meta-witherspoon/recipes-phosphor/settings/phosphor-settings-read-settings-mrw-native.bbappend
index 72d991c..aa8149c 100644
--- a/meta-witherspoon/recipes-phosphor/settings/phosphor-settings-read-settings-mrw-native.bbappend
+++ b/meta-witherspoon/recipes-phosphor/settings/phosphor-settings-read-settings-mrw-native.bbappend
@@ -1 +1,2 @@
 FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
+MRW_EXPRESSION_VARS = "-v PS_DERATING=${POWER_SUPPLY_DERATING_FACTOR}"
diff --git a/meta-witherspoon/recipes-phosphor/settings/phosphor-settings-read-settings-mrw-native/mrw-override-settings.yaml b/meta-witherspoon/recipes-phosphor/settings/phosphor-settings-read-settings-mrw-native/mrw-override-settings.yaml
index 0bfd515..c823896 100644
--- a/meta-witherspoon/recipes-phosphor/settings/phosphor-settings-read-settings-mrw-native/mrw-override-settings.yaml
+++ b/meta-witherspoon/recipes-phosphor/settings/phosphor-settings-read-settings-mrw-native/mrw-override-settings.yaml
@@ -5,7 +5,7 @@
               Default: 0
               Validation:
                   Type: "range"
-                  Validator: "MRW_OPEN_POWER_SOFT_MIN_PCAP_WATTS..MRW_OPEN_POWER_N_PLUS_ONE_BULK_POWER_LIMIT_WATTS"
+                  Validator: "[[MRW_OPEN_POWER_SOFT_MIN_PCAP_WATTS/(PS_DERATING/100)]]..[[MRW_OPEN_POWER_N_PLUS_ONE_BULK_POWER_LIMIT_WATTS/(PS_DERATING/100)]]"
                   Unit: "Watts"
           PowerCapEnable:
                Default: 'false'