diff --git a/html/includes/graphs/application/dhcp-stats_stats.inc.php b/html/includes/graphs/application/dhcp-stats_stats.inc.php
index e742f472b2..83a3addf58 100644
--- a/html/includes/graphs/application/dhcp-stats_stats.inc.php
+++ b/html/includes/graphs/application/dhcp-stats_stats.inc.php
@@ -28,7 +28,7 @@ $array = array(
 );
 
 $i = 0;
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     foreach ($array as $ds => $var) {
         $rrd_list[$i]['filename'] = $rrd_filename;
         $rrd_list[$i]['descr']    = $var['descr'];
diff --git a/html/includes/graphs/application/exim-stats_frozen.inc.php b/html/includes/graphs/application/exim-stats_frozen.inc.php
index 16a823e65d..4be9a4d58d 100644
--- a/html/includes/graphs/application/exim-stats_frozen.inc.php
+++ b/html/includes/graphs/application/exim-stats_frozen.inc.php
@@ -39,7 +39,7 @@ $array = array(
 );
 
 $i = 0;
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     foreach ($array as $ds => $var) {
         $rrd_list[$i]['filename'] = $rrd_filename;
         $rrd_list[$i]['descr']    = $var['descr'];
diff --git a/html/includes/graphs/application/exim-stats_queue.inc.php b/html/includes/graphs/application/exim-stats_queue.inc.php
index 4c6facaeef..2651810a62 100644
--- a/html/includes/graphs/application/exim-stats_queue.inc.php
+++ b/html/includes/graphs/application/exim-stats_queue.inc.php
@@ -39,7 +39,7 @@ $array = array(
 );
 
 $i = 0;
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     foreach ($array as $ds => $var) {
         $rrd_list[$i]['filename'] = $rrd_filename;
         $rrd_list[$i]['descr']    = $var['descr'];
diff --git a/html/includes/graphs/application/fail2ban_banned.inc.php b/html/includes/graphs/application/fail2ban_banned.inc.php
index 27cd9f1245..2a569411bf 100644
--- a/html/includes/graphs/application/fail2ban_banned.inc.php
+++ b/html/includes/graphs/application/fail2ban_banned.inc.php
@@ -13,7 +13,7 @@ $transparency  = 15;
 
 $rrd_filename = rrd_name($device['hostname'], array('app', $app['app_type'], $app['app_id']));
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/fbsd-nfs-client_cache.inc.php b/html/includes/graphs/application/fbsd-nfs-client_cache.inc.php
index 411429bcf1..d48cc8ef96 100644
--- a/html/includes/graphs/application/fbsd-nfs-client_cache.inc.php
+++ b/html/includes/graphs/application/fbsd-nfs-client_cache.inc.php
@@ -14,7 +14,7 @@ $transparency  = 15;
 
 $rrd_filename = rrd_name($device['hostname'], array('app', $name, $app_id));
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/fbsd-nfs-client_rpc.inc.php b/html/includes/graphs/application/fbsd-nfs-client_rpc.inc.php
index a1a836e3e3..0ce3049d84 100644
--- a/html/includes/graphs/application/fbsd-nfs-client_rpc.inc.php
+++ b/html/includes/graphs/application/fbsd-nfs-client_rpc.inc.php
@@ -14,7 +14,7 @@ $transparency  = 15;
 
 $rrd_filename = rrd_name($device['hostname'], array('app', $name, $app_id));
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/fbsd-nfs-client_stats.inc.php b/html/includes/graphs/application/fbsd-nfs-client_stats.inc.php
index 15bcef83ce..0d06772140 100644
--- a/html/includes/graphs/application/fbsd-nfs-client_stats.inc.php
+++ b/html/includes/graphs/application/fbsd-nfs-client_stats.inc.php
@@ -14,7 +14,7 @@ $transparency  = 15;
 
 $rrd_filename = rrd_name($device['hostname'], array('app', $name, $app_id));
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/fbsd-nfs-server_cache.inc.php b/html/includes/graphs/application/fbsd-nfs-server_cache.inc.php
index 52cd4e63e6..39d9339973 100644
--- a/html/includes/graphs/application/fbsd-nfs-server_cache.inc.php
+++ b/html/includes/graphs/application/fbsd-nfs-server_cache.inc.php
@@ -14,7 +14,7 @@ $transparency  = 15;
 
 $rrd_filename = rrd_name($device['hostname'], array('app', $name, $app_id));
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/fbsd-nfs-server_gathering.inc.php b/html/includes/graphs/application/fbsd-nfs-server_gathering.inc.php
index 1ba27e4bb2..6fca8ef345 100644
--- a/html/includes/graphs/application/fbsd-nfs-server_gathering.inc.php
+++ b/html/includes/graphs/application/fbsd-nfs-server_gathering.inc.php
@@ -14,7 +14,7 @@ $transparency  = 15;
 
 $rrd_filename = rrd_name($device['hostname'], array('app', $name, $app_id));
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/fbsd-nfs-server_stats.inc.php b/html/includes/graphs/application/fbsd-nfs-server_stats.inc.php
index fe64ade9e8..921ff56503 100644
--- a/html/includes/graphs/application/fbsd-nfs-server_stats.inc.php
+++ b/html/includes/graphs/application/fbsd-nfs-server_stats.inc.php
@@ -14,7 +14,7 @@ $transparency  = 15;
 
 $rrd_filename = rrd_name($device['hostname'], array('app', $name, $app_id));
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/nfs-stats.inc.php b/html/includes/graphs/application/nfs-stats.inc.php
index fd29a9a1fc..a533166a6b 100644
--- a/html/includes/graphs/application/nfs-stats.inc.php
+++ b/html/includes/graphs/application/nfs-stats.inc.php
@@ -74,7 +74,7 @@ $array        = array(
 
 $i = 0;
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     foreach ($array as $ds => $var) {
         $rrd_list[$i]['filename'] = $rrd_filename;
         $rrd_list[$i]['descr']    = $var['descr'];
diff --git a/html/includes/graphs/application/nfs-v3-stats_fh.inc.php b/html/includes/graphs/application/nfs-v3-stats_fh.inc.php
index 13cb803688..a3477ceda4 100644
--- a/html/includes/graphs/application/nfs-v3-stats_fh.inc.php
+++ b/html/includes/graphs/application/nfs-v3-stats_fh.inc.php
@@ -21,7 +21,7 @@ $array = array(
 
 $i = 0;
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     foreach ($array as $ds => $var) {
         $rrd_list[$i]['filename'] = $rrd_filename;
         $rrd_list[$i]['descr']    = $var['descr'];
diff --git a/html/includes/graphs/application/nfs-v3-stats_io.inc.php b/html/includes/graphs/application/nfs-v3-stats_io.inc.php
index bbc929774c..65bfe6fe68 100644
--- a/html/includes/graphs/application/nfs-v3-stats_io.inc.php
+++ b/html/includes/graphs/application/nfs-v3-stats_io.inc.php
@@ -18,7 +18,7 @@ $array = array(
 
 $i = 0;
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     foreach ($array as $ds => $var) {
         $rrd_list[$i]['filename'] = $rrd_filename;
         $rrd_list[$i]['descr']    = $var['descr'];
diff --git a/html/includes/graphs/application/nfs-v3-stats_net.inc.php b/html/includes/graphs/application/nfs-v3-stats_net.inc.php
index 156ebd3b79..11cb003a54 100644
--- a/html/includes/graphs/application/nfs-v3-stats_net.inc.php
+++ b/html/includes/graphs/application/nfs-v3-stats_net.inc.php
@@ -20,7 +20,7 @@ $array = array(
 
 $i = 0;
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     foreach ($array as $ds => $var) {
         $rrd_list[$i]['filename'] = $rrd_filename;
         $rrd_list[$i]['descr']    = $var['descr'];
diff --git a/html/includes/graphs/application/nfs-v3-stats_ra.inc.php b/html/includes/graphs/application/nfs-v3-stats_ra.inc.php
index 24e7fdc621..ffee4b8f2e 100644
--- a/html/includes/graphs/application/nfs-v3-stats_ra.inc.php
+++ b/html/includes/graphs/application/nfs-v3-stats_ra.inc.php
@@ -28,7 +28,7 @@ $array = array(
 
 $i = 0;
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     foreach ($array as $ds => $var) {
         $rrd_list[$i]['filename'] = $rrd_filename;
         $rrd_list[$i]['descr']    = $var['descr'];
diff --git a/html/includes/graphs/application/nfs-v3-stats_rc.inc.php b/html/includes/graphs/application/nfs-v3-stats_rc.inc.php
index 70560a51ca..c3e9cf28fa 100644
--- a/html/includes/graphs/application/nfs-v3-stats_rc.inc.php
+++ b/html/includes/graphs/application/nfs-v3-stats_rc.inc.php
@@ -19,7 +19,7 @@ $array = array(
 
 $i = 0;
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     foreach ($array as $ds => $var) {
         $rrd_list[$i]['filename'] = $rrd_filename;
         $rrd_list[$i]['descr']    = $var['descr'];
diff --git a/html/includes/graphs/application/nfs-v3-stats_rpc.inc.php b/html/includes/graphs/application/nfs-v3-stats_rpc.inc.php
index 95b84fe477..a21d1de56c 100644
--- a/html/includes/graphs/application/nfs-v3-stats_rpc.inc.php
+++ b/html/includes/graphs/application/nfs-v3-stats_rpc.inc.php
@@ -21,7 +21,7 @@ $array = array(
 
 $i = 0;
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     foreach ($array as $ds => $var) {
         $rrd_list[$i]['filename'] = $rrd_filename;
         $rrd_list[$i]['descr']    = $var['descr'];
diff --git a/html/includes/graphs/application/nfs-v3-stats_stats.inc.php b/html/includes/graphs/application/nfs-v3-stats_stats.inc.php
index 92c3cc6a2f..4f82272d2c 100644
--- a/html/includes/graphs/application/nfs-v3-stats_stats.inc.php
+++ b/html/includes/graphs/application/nfs-v3-stats_stats.inc.php
@@ -38,7 +38,7 @@ $array         = array(
 
 $i = 0;
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     foreach ($array as $ds => $var) {
         $rrd_list[$i]['filename'] = $rrd_filename;
         $rrd_list[$i]['descr']    = $var['descr'];
diff --git a/html/includes/graphs/application/os-updates_packages.inc.php b/html/includes/graphs/application/os-updates_packages.inc.php
index 18973ec499..b7b080e0bd 100644
--- a/html/includes/graphs/application/os-updates_packages.inc.php
+++ b/html/includes/graphs/application/os-updates_packages.inc.php
@@ -20,7 +20,7 @@ $array = array(
 );
 
 $i = 0;
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     foreach ($array as $ds => $var) {
         $rrd_list[$i]['filename'] = $rrd_filename;
         $rrd_list[$i]['descr']    = $var['descr'];
diff --git a/html/includes/graphs/application/postfix_bytes.inc.php b/html/includes/graphs/application/postfix_bytes.inc.php
index 59a5f8b136..8727feaa83 100644
--- a/html/includes/graphs/application/postfix_bytes.inc.php
+++ b/html/includes/graphs/application/postfix_bytes.inc.php
@@ -14,7 +14,7 @@ $transparency  = 15;
 
 $rrd_filename = rrd_name($device['hostname'], array('app', $name, $app_id));
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/postfix_deferral.inc.php b/html/includes/graphs/application/postfix_deferral.inc.php
index 2e1988b32c..c166971720 100644
--- a/html/includes/graphs/application/postfix_deferral.inc.php
+++ b/html/includes/graphs/application/postfix_deferral.inc.php
@@ -14,7 +14,7 @@ $transparency  = 15;
 
 $rrd_filename = rrd_name($device['hostname'], array('app', $name, $app_id));
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/postfix_messages.inc.php b/html/includes/graphs/application/postfix_messages.inc.php
index d53bc73de1..5f06329443 100644
--- a/html/includes/graphs/application/postfix_messages.inc.php
+++ b/html/includes/graphs/application/postfix_messages.inc.php
@@ -14,7 +14,7 @@ $transparency  = 15;
 
 $rrd_filename = rrd_name($device['hostname'], array('app', $name, $app_id));
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/postfix_qstats.inc.php b/html/includes/graphs/application/postfix_qstats.inc.php
index 3549302e77..2fe798e217 100644
--- a/html/includes/graphs/application/postfix_qstats.inc.php
+++ b/html/includes/graphs/application/postfix_qstats.inc.php
@@ -14,7 +14,7 @@ $transparency  = 15;
 
 $rrd_filename = rrd_name($device['hostname'], array('app', $name, $app_id));
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/postfix_rejects.inc.php b/html/includes/graphs/application/postfix_rejects.inc.php
index 726ea414e3..ce7d0d0fec 100644
--- a/html/includes/graphs/application/postfix_rejects.inc.php
+++ b/html/includes/graphs/application/postfix_rejects.inc.php
@@ -14,7 +14,7 @@ $transparency  = 15;
 
 $rrd_filename = rrd_name($device['hostname'], array('app', $name, $app_id));
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/postfix_sr.inc.php b/html/includes/graphs/application/postfix_sr.inc.php
index 3ba7d66615..4598a7a73e 100644
--- a/html/includes/graphs/application/postfix_sr.inc.php
+++ b/html/includes/graphs/application/postfix_sr.inc.php
@@ -14,7 +14,7 @@ $transparency  = 15;
 
 $rrd_filename = rrd_name($device['hostname'], array('app', $name, $app_id));
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/postgres_backends.inc.php b/html/includes/graphs/application/postgres_backends.inc.php
index 8d38bba66c..ccdd13e454 100644
--- a/html/includes/graphs/application/postgres_backends.inc.php
+++ b/html/includes/graphs/application/postgres_backends.inc.php
@@ -20,7 +20,7 @@ if (isset($vars['database'])) {
 
 $rrd_filename = rrd_name($device['hostname'], $rrd_name_array);
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/postgres_cr.inc.php b/html/includes/graphs/application/postgres_cr.inc.php
index 62c288f33f..a3281d910e 100644
--- a/html/includes/graphs/application/postgres_cr.inc.php
+++ b/html/includes/graphs/application/postgres_cr.inc.php
@@ -20,7 +20,7 @@ if (isset($vars['database'])) {
 
 $rrd_filename = rrd_name($device['hostname'], $rrd_name_array);
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/postgres_hr.inc.php b/html/includes/graphs/application/postgres_hr.inc.php
index cd94d68dc6..ad464ddb91 100644
--- a/html/includes/graphs/application/postgres_hr.inc.php
+++ b/html/includes/graphs/application/postgres_hr.inc.php
@@ -21,7 +21,7 @@ if (isset($vars['database'])) {
 
 $rrd_filename = rrd_name($device['hostname'], $rrd_name_array);
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/postgres_index.inc.php b/html/includes/graphs/application/postgres_index.inc.php
index 681eb98672..6a3bc99515 100644
--- a/html/includes/graphs/application/postgres_index.inc.php
+++ b/html/includes/graphs/application/postgres_index.inc.php
@@ -20,7 +20,7 @@ if (isset($vars['database'])) {
 
 $rrd_filename = rrd_name($device['hostname'], $rrd_name_array);
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/postgres_rows.inc.php b/html/includes/graphs/application/postgres_rows.inc.php
index 26e5d9b662..04f9034723 100644
--- a/html/includes/graphs/application/postgres_rows.inc.php
+++ b/html/includes/graphs/application/postgres_rows.inc.php
@@ -20,7 +20,7 @@ if (isset($vars['database'])) {
 
 $rrd_filename = rrd_name($device['hostname'], $rrd_name_array);
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/postgres_sequential.inc.php b/html/includes/graphs/application/postgres_sequential.inc.php
index 297b124f59..2270f12d4a 100644
--- a/html/includes/graphs/application/postgres_sequential.inc.php
+++ b/html/includes/graphs/application/postgres_sequential.inc.php
@@ -20,7 +20,7 @@ if (isset($vars['database'])) {
 
 $rrd_filename = rrd_name($device['hostname'], $rrd_name_array);
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/powerdns-recursor.inc.php b/html/includes/graphs/application/powerdns-recursor.inc.php
index 72a6221cd8..cd9b2ae3a9 100644
--- a/html/includes/graphs/application/powerdns-recursor.inc.php
+++ b/html/includes/graphs/application/powerdns-recursor.inc.php
@@ -24,7 +24,7 @@
  */
 
 $rrd = rrd_name($device['hostname'], array('app', 'powerdns-recursor', $app['app_id']));
-if (is_file($rrd)) {
+if (rrdtool_check_rrd_exists($rrd)) {
     $rrd_filename = $rrd;
 }
 $simple_rrd = true;
diff --git a/html/includes/graphs/application/powerdns-recursor_answers.inc.php b/html/includes/graphs/application/powerdns-recursor_answers.inc.php
index bd40bea809..ae0e8a8285 100644
--- a/html/includes/graphs/application/powerdns-recursor_answers.inc.php
+++ b/html/includes/graphs/application/powerdns-recursor_answers.inc.php
@@ -29,7 +29,7 @@ $colours = 'oranges';
 $unit_text = 'Answers/sec';
 $print_total = true;
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'ds' => 'answers0-1',
diff --git a/html/includes/graphs/application/powerdns-recursor_cache_performance.inc.php b/html/includes/graphs/application/powerdns-recursor_cache_performance.inc.php
index f871c9e676..42bbcfe673 100644
--- a/html/includes/graphs/application/powerdns-recursor_cache_performance.inc.php
+++ b/html/includes/graphs/application/powerdns-recursor_cache_performance.inc.php
@@ -27,7 +27,7 @@ include 'powerdns-recursor.inc.php';
 $colours = 'mixed';
 $unit_text = 'Packets/sec';
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/powerdns-recursor_cache_size.inc.php b/html/includes/graphs/application/powerdns-recursor_cache_size.inc.php
index dc46388b73..f5e528fec6 100644
--- a/html/includes/graphs/application/powerdns-recursor_cache_size.inc.php
+++ b/html/includes/graphs/application/powerdns-recursor_cache_size.inc.php
@@ -28,7 +28,7 @@ include 'powerdns-recursor.inc.php';
 $colours = 'purples';
 $unit_text = 'Entries';
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/powerdns-recursor_outqueries.inc.php b/html/includes/graphs/application/powerdns-recursor_outqueries.inc.php
index b260e31999..e01d488406 100644
--- a/html/includes/graphs/application/powerdns-recursor_outqueries.inc.php
+++ b/html/includes/graphs/application/powerdns-recursor_outqueries.inc.php
@@ -28,7 +28,7 @@ include 'powerdns-recursor.inc.php';
 $colours = 'mixed';
 $unit_text = 'Queries/sec';
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,
diff --git a/html/includes/graphs/application/powerdns-recursor_questions.inc.php b/html/includes/graphs/application/powerdns-recursor_questions.inc.php
index e9a0762689..a9a26f97f6 100644
--- a/html/includes/graphs/application/powerdns-recursor_questions.inc.php
+++ b/html/includes/graphs/application/powerdns-recursor_questions.inc.php
@@ -28,7 +28,7 @@ include 'powerdns-recursor.inc.php';
 $colours = 'mixed';
 $unit_text = 'Questions/sec';
 
-if (is_file($rrd_filename)) {
+if (rrdtool_check_rrd_exists($rrd_filename)) {
     $rrd_list = array(
         array(
             'filename' => $rrd_filename,