diff --git a/.github/workflows/php.yml b/.github/workflows/php.yml
index c596c38..12d1283 100644
--- a/.github/workflows/php.yml
+++ b/.github/workflows/php.yml
@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ['7.2', '7.3', '7.4', '8.0', '8.1']
+        php: ['7.2', '7.3', '7.4', '8.0', '8.1', '8.2']
         os: ['ubuntu-latest']
 
     steps:
@@ -33,6 +33,7 @@ jobs:
       - name: Setup dependencies
         run: composer require -n --no-progress overtrue/phplint
           && git clone --single-branch --branch master https://github.com/Icinga/icingaweb2.git vendor/icingaweb2
+          && git clone --single-branch --branch master https://github.com/Icinga/icingadb-web.git vendor/icingadb-web
           && git clone --single-branch --branch snapshot/nightly https://github.com/Icinga/icinga-php-library.git vendor/icinga-php-library
           && git clone --single-branch --branch snapshot/nightly https://github.com/Icinga/icinga-php-thirdparty.git vendor/icinga-php-thirdparty
 
diff --git a/application/clicommands/Icinga2Command.php b/application/clicommands/Icinga2Command.php
index 816e063..e0e0ee4 100644
--- a/application/clicommands/Icinga2Command.php
+++ b/application/clicommands/Icinga2Command.php
@@ -138,6 +138,8 @@ EOT
                 }
             }
 
+            assert(isset($service), '$service not initialized in the loop');
+
             $monObj = $service
                 ? [
                     "apply Service \"{$icinga2CfgObjPrefix}_{$checkCommand}\" {",
diff --git a/application/forms/TimeRangePicker/CustomForm.php b/application/forms/TimeRangePicker/CustomForm.php
index 89b5833..8627267 100644
--- a/application/forms/TimeRangePicker/CustomForm.php
+++ b/application/forms/TimeRangePicker/CustomForm.php
@@ -126,6 +126,9 @@ class CustomForm extends Form
             ]);
         }
 
+        assert(isset($elementDecorators), '$elementDecorators not initialized in the loop');
+        assert(isset($element), '$element not initialized in the loop');
+
         $decorators = [];
         foreach ($elementDecorators as $key => $decorator) {
             if ($key === 'Zend_Form_Decorator_ViewHelper') {
diff --git a/library/Graphite/Graphing/Template.php b/library/Graphite/Graphing/Template.php
index a030fb7..0950fed 100644
--- a/library/Graphite/Graphing/Template.php
+++ b/library/Graphite/Graphing/Template.php
@@ -203,6 +203,7 @@ class Template
                 }
             }
             unset($_);
+            assert(isset($nextCurveName), 'loop did not initialize variable $nextCurveName');
 
             $allowedNextCurveMetricsPerCurrentCurveName = [];
             foreach ($currentCombination as $currentCurveName => $currentCurveMetric) {
diff --git a/library/Graphite/Web/Controller/MonitoringAwareController.php b/library/Graphite/Web/Controller/MonitoringAwareController.php
index dca2ebd..d4f1a07 100644
--- a/library/Graphite/Web/Controller/MonitoringAwareController.php
+++ b/library/Graphite/Web/Controller/MonitoringAwareController.php
@@ -22,6 +22,9 @@ abstract class MonitoringAwareController extends Controller
     /** @var bool Whether to use icingadb as the backend */
     protected $useIcingadbAsBackend = false;
 
+    /** @var  MonitoringBackend */
+    protected $backend;
+
     /**
      * Restrict the given monitored object query for the currently authenticated user
      *
diff --git a/library/Graphite/Web/Widget/Graphs.php b/library/Graphite/Web/Widget/Graphs.php
index e18b8da..29c3160 100644
--- a/library/Graphite/Web/Widget/Graphs.php
+++ b/library/Graphite/Web/Widget/Graphs.php
@@ -134,7 +134,7 @@ abstract class Graphs extends AbstractWidget
      *
      * @param   MonitoredObject $object
      *
-     * @return  static
+     * @return  ?static
      */
     public static function forMonitoredObject(MonitoredObject $object)
     {