diff --git a/xCAT-client/bin/pping b/xCAT-client/bin/pping
index 0b47fe663..4bc3af11b 100755
--- a/xCAT-client/bin/pping
+++ b/xCAT-client/bin/pping
@@ -199,7 +199,7 @@ sub nmap_pping {
         @nmap_options = xCAT::TableUtils->get_site_attribute("nmapoptions");
         $more_options = $nmap_options[0];
     }
-    open(FPING, "nmap -PE --system-dns --send-ip -sP $more_options " . join(' ', @$nodes) . " 2> /dev/null|") or die("Cannot open nmap pipe: $!");
+    open(FPING, "nmap -PE --system-dns --unprivileged --send-ip -sP $more_options " . join(' ', @$nodes) . " 2> /dev/null|") or die("Cannot open nmap pipe: $!");
     my $node;
     while (<FPING>) {
         if (/Host (.*) \(.*\) appears to be up/) {