diff --git a/plugins/xen/xen_cpu_v2 b/plugins/xen/xen_cpu_v2
index 75c9a951..aa58184c 100755
--- a/plugins/xen/xen_cpu_v2
+++ b/plugins/xen/xen_cpu_v2
@@ -171,8 +171,12 @@ while (($key, $value) = each %dom)
 	
 	# Calc a percentage based on the _total_ available CPU time
 	$tmp = 0;
-	$tmp = ( $dom{$key}->{'diff'} / $tcpuavail ) * 100;
-	$dom{$key}->{'pc_tcpu'} = sprintf("%.2f", $tmp);
+	if ($tcpuavail != 0) {
+		$tmp = ( $dom{$key}->{'diff'} / $tcpuavail ) * 100;
+		$dom{$key}->{'pc_tcpu'} = sprintf("%.2f", $tmp);
+	} else {
+		$dom{$key}->{'pc_tcpu'} = "U";
+	}
 	
 	if ( $debug )
 	{