diff --git a/openpower/configs/hostboot/witherspoon.config b/openpower/configs/hostboot/witherspoon.config
index bc91d5a..a3380fb 100755
--- a/openpower/configs/hostboot/witherspoon.config
+++ b/openpower/configs/hostboot/witherspoon.config
@@ -1,6 +1,8 @@
-# The Serial Flash Controller is the AST2400 BMC.
-set   SFC_IS_AST2500
+# The BMC MBOX Protocol is used to access PNOR
+unset SFC_IS_AST2500
 unset SFC_IS_AST2400
+set   PNORDD_IS_BMCMBOX
+unset PNORDD_IS_SFC
 unset BMC_DOES_SFC_INIT
 unset SFC_IS_IBM_DPSS
 set   ALLOW_MICRON_PNOR
diff --git a/openpower/configs/hostboot/zaius.config b/openpower/configs/hostboot/zaius.config
index bc87d42..cd0390e 100755
--- a/openpower/configs/hostboot/zaius.config
+++ b/openpower/configs/hostboot/zaius.config
@@ -1,6 +1,8 @@
-# The Serial Flash Controller is the AST2500 BMC.
-set   SFC_IS_AST2500
+# The BMC MBOX Protocol is used to access PNOR
+unset SFC_IS_AST2500
 unset SFC_IS_AST2400
+set   PNORDD_IS_BMCMBOX
+unset PNORDD_IS_SFC
 unset BMC_DOES_SFC_INIT
 unset SFC_IS_IBM_DPSS
 set   ALLOW_MICRON_PNOR