diff --git a/include/management/class_management.inc b/include/management/class_management.inc
index d613a0c2c65c3b9a34112baec3d8a4b2de645a6b..de189937b2ac4fdce32ab55648b4257e72a312b5 100755
--- a/include/management/class_management.inc
+++ b/include/management/class_management.inc
@@ -99,11 +99,11 @@ class management implements FusionDirectoryDialog
     global $config, $class_mapping;
 
     if ($objectTypes === FALSE) {
-      $plInfos     = pluglist::pluginInfos(get_class($this));
+      $plInfos     = pluglist::pluginInfos(static::class);
       $objectTypes = $plInfos['plManages'];
     }
 
-    if (!preg_match('/^geticon/', $this->icon)) {
+    if (!preg_match('/^geticon/', (string) $this->icon)) {
       $this->icon = get_template_path($this->icon);
     }
 
@@ -111,8 +111,8 @@ class management implements FusionDirectoryDialog
     foreach ($objectTypes as $key => $type) {
       try {
         objects::infos($type);
-        $objectTypes[$key] = strtoupper($type);
-      } catch (NonExistingObjectTypeException $e) {
+        $objectTypes[$key] = strtoupper((string) $type);
+      } catch (NonExistingObjectTypeException) {
         unset($objectTypes[$key]);
       }
     }
@@ -156,7 +156,7 @@ class management implements FusionDirectoryDialog
 
   protected function setUpHeadline ()
   {
-    $plInfos = pluglist::pluginInfos(get_class($this));
+    $plInfos = pluglist::pluginInfos(static::class);
 
     $this->headline = $plInfos['plShortName'];
     $this->title    = $plInfos['plTitle'];
@@ -362,7 +362,7 @@ class management implements FusionDirectoryDialog
 
     if (!isset($this->columnConfiguration)) {
       // LDAP configuration
-      $this->columnConfiguration = $config->getManagementConfig(get_class($this));
+      $this->columnConfiguration = $config->getManagementConfig(static::class);
     }
 
     if (!isset($this->columnConfiguration)) {
@@ -430,8 +430,8 @@ class management implements FusionDirectoryDialog
 
   protected function handleSubAction (array $action): bool
   {
-    if (preg_match('/^tab_/', $action['subaction'])) {
-      $tab = preg_replace('/^tab_/', '', $action['subaction']);
+    if (preg_match('/^tab_/', (string) $action['subaction'])) {
+      $tab = preg_replace('/^tab_/', '', (string) $action['subaction']);
       if (isset($this->tabObject->by_object[$tab])) {
         $this->tabObject->current = $tab;
       } else {
@@ -768,7 +768,7 @@ class management implements FusionDirectoryDialog
     if (static::$skipTemplates) {
       return;
     }
-    $type = preg_replace('/^template_/', '', $action['subaction']);
+    $type = preg_replace('/^template_/', '', (string) $action['subaction']);
 
     $this->currentDn = 'new';
 
@@ -793,7 +793,7 @@ class management implements FusionDirectoryDialog
       }
       $type = $this->listing->getEntry($dn)->getTemplatedType();
     } else {
-      $type = preg_replace('/^apply_/', '', $action['subaction']);
+      $type = preg_replace('/^apply_/', '', (string) $action['subaction']);
     }
     $this->dialogObject = new templateDialog($this, $type, $dn);
   }
@@ -1124,7 +1124,7 @@ class management implements FusionDirectoryDialog
       } else {
         $error = new FusionDirectoryPermissionError(msgPool::permDelete($dn));
         $error->display();
-        logging::log('security', 'management/' . get_class($this), $dn, [], 'Tried to trick deletion.');
+        logging::log('security', 'management/' . static::class, $dn, [], 'Tried to trick deletion.');
       }
     }