diff --git a/html/includes/graphs/application/nfs-stats.inc.php b/html/includes/graphs/application/nfs-stats.inc.php
index 02d82cd12c..edebca8aef 100644
--- a/html/includes/graphs/application/nfs-stats.inc.php
+++ b/html/includes/graphs/application/nfs-stats.inc.php
@@ -4,7 +4,7 @@ $scale_min    = 0;
 $colours      = 'mixed';
 $unit_text    = 'Operation';
 $unitlen      = 9;
-$stack	      = 0;
+$dostack      = 0;
 $rrd_filename = $config['rrd_dir'].'/'.$device['hostname'].'/app-nfsstats-'.$app['app_id'].'.rrd';
 $array        = array(
                  'total' => array(
diff --git a/html/includes/graphs/generic_multi_line_exact_numbers.inc.php b/html/includes/graphs/generic_multi_line_exact_numbers.inc.php
index 5561286ef4..ee2e723409 100644
--- a/html/includes/graphs/generic_multi_line_exact_numbers.inc.php
+++ b/html/includes/graphs/generic_multi_line_exact_numbers.inc.php
@@ -88,7 +88,7 @@ foreach ($rrd_list as $rrd) {
         $t_defname = $g_defname;
     }
 
-    if ($i && ($stack === 1)) {
+    if ($i && ($dostack === 1)) {
     	$stack = ':STACK';
     }