diff --git a/xCAT-server/lib/xcat/plugins/pdu.pm b/xCAT-server/lib/xcat/plugins/pdu.pm
index 895d56184..17e66f50c 100644
--- a/xCAT-server/lib/xcat/plugins/pdu.pm
+++ b/xCAT-server/lib/xcat/plugins/pdu.pm
@@ -339,7 +339,7 @@ sub outletpower {
 
     my $oid = ".1.3.6.1.4.1.2.6.223.8.2.2.1.11";
     my $type = "INTEGER";
-    if ($session->newmib) {
+    if ($session->{newmib}) {
         $oid = ".1.3.6.1.4.1.2.6.223.8.2.2.1.13";
     }
 
@@ -393,7 +393,7 @@ sub outletstat {
     my $oid = ".1.3.6.1.4.1.2.6.223.8.2.2.1.11";
     my $output;
     my $statstr;
-    if ($session->newmib) {
+    if ($session->{newmib}) {
         $oid = ".1.3.6.1.4.1.2.6.223.8.2.2.1.13";
     }
 
@@ -435,11 +435,11 @@ sub connectTopdu {
     unless ($session) {
         return;
     }
-    $session->newmib = 0;
+    $session->{newmib} = 0;
     my $pduversion = $session->get(".1.3.6.1.4.1.2.6.223.7.3.0");
     if ($pduversion =~ /(\d+)\.(\d+)_(\d+)/) {
         if ($1 >= 1 and $2 >= 3 and $3 >= 3) {
-                $session->newmib = 1;
+                $session->{newmib} = 1;
         }
     }