diff --git a/library/Perfdatagraphs/Common/PerfdataChart.php b/library/Perfdatagraphs/Common/PerfdataChart.php
index 3e4948b..9b95914 100644
--- a/library/Perfdatagraphs/Common/PerfdataChart.php
+++ b/library/Perfdatagraphs/Common/PerfdataChart.php
@@ -5,6 +5,7 @@
 use Icinga\Module\Perfdatagraphs\Widget\QuickActions;
 
 use Icinga\Application\Benchmark;
+use Icinga\Application\Logger;
 use Icinga\Util\Json;
 
 use ipl\Html\Html;
@@ -127,6 +128,7 @@ public function createChart(string $hostName, string $serviceName, string $check
             // Error handling, if this gets too long, we could move this to a method.
             if ($perfdata->hasErrors()) {
                 $msg = sprintf($this->translate('Error while fetching data: %s'), join(' ', $perfdata->getErrors()));
+                Logger::debug('Error while fetching data: %s', Json::sanitize($perfdata));
             }
 
             if ($perfdata->isEmpty()) {
@@ -135,6 +137,7 @@ public function createChart(string $hostName, string $serviceName, string $check
 
             if (!$perfdata->isValid()) {
                 $msg = $msg . ' ' . sprintf($this->translate('Invalid data received: %s'), join(' ', $perfdata->getErrors()));
+                Logger::debug('Invalid data received: %s', Json::sanitize($perfdata));
             }
 
             if (isset($msg)) {