diff --git a/src/Plugin/FillPdfActionPlugin/FillPdfSaveAction.php b/src/Plugin/FillPdfActionPlugin/FillPdfSaveAction.php
index 280a0607496de841a3318fd254d8d33838464f70..fa91c7303728cbe70e06a202244804af278aa6cd 100644
--- a/src/Plugin/FillPdfActionPlugin/FillPdfSaveAction.php
+++ b/src/Plugin/FillPdfActionPlugin/FillPdfSaveAction.php
@@ -20,28 +20,24 @@ use Symfony\Component\HttpFoundation\RedirectResponse;
  */
 class FillPdfSaveAction extends FillPdfActionPluginBase {
 
-  /**
-   * The FillPdf output handler.
-   *
-   * @var \Drupal\fillpdf\OutputHandler
-   */
-  protected $outputHandler;
-
   /**
    * Constructs a \Drupal\Component\Plugin\PluginBase object.
    *
-   * @param \Drupal\fillpdf\OutputHandler $output_handler
-   *   The FillPdf output handler.
    * @param array $configuration
    *   A configuration array containing information about the plugin instance.
    * @param string $plugin_id
    *   The plugin_id for the plugin instance.
    * @param mixed $plugin_definition
    *   The plugin implementation definition.
+   * @param \Drupal\fillpdf\OutputHandler $outputHandler
+   *   The fillpdf.output_handler service.
    */
-  public function __construct(OutputHandler $output_handler, array $configuration, $plugin_id, $plugin_definition) {
-    $this->outputHandler = $output_handler;
-
+  public function __construct(
+    array $configuration,
+    $plugin_id,
+    $plugin_definition,
+    protected OutputHandler $outputHandler,
+  ) {
     parent::__construct($configuration, $plugin_id, $plugin_definition);
   }
 
@@ -50,10 +46,10 @@ class FillPdfSaveAction extends FillPdfActionPluginBase {
    */
   public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
     return new static(
-      $container->get('fillpdf.output_handler'),
       $configuration,
       $plugin_id,
-      $plugin_definition
+      $plugin_definition,
+      $container->get('fillpdf.output_handler'),
     );
   }
 
diff --git a/src/Plugin/PdfBackend/LocalServerPdfBackend.php b/src/Plugin/PdfBackend/LocalServerPdfBackend.php
index 1a2902d24d229c18c7692191ead575c588278e0d..f166dd758d6fbda108dc7c0ca64b3d8cc823561e 100644
--- a/src/Plugin/PdfBackend/LocalServerPdfBackend.php
+++ b/src/Plugin/PdfBackend/LocalServerPdfBackend.php
@@ -32,13 +32,6 @@ class LocalServerPdfBackend extends PdfBackendBase implements ContainerFactoryPl
    */
   protected $fileSystem;
 
-  /**
-   * The Guzzle http client.
-   *
-   * @var \GuzzleHttp\Client
-   */
-  protected $httpClient;
-
   /**
    * Constructs a LocalServerPdfBackend plugin object.
    *
@@ -48,12 +41,16 @@ class LocalServerPdfBackend extends PdfBackendBase implements ContainerFactoryPl
    *   The plugin_id for the plugin instance.
    * @param array $plugin_definition
    *   The plugin implementation definition.
-   * @param \GuzzleHttp\Client $http_client
+   * @param \GuzzleHttp\Client $httpClient
    *   The Guzzle http client.
    */
-  public function __construct(array $configuration, $plugin_id, array $plugin_definition, Client $http_client) {
+  public function __construct(
+    array $configuration,
+    $plugin_id,
+    array $plugin_definition,
+    protected Client $httpClient,
+  ) {
     parent::__construct($configuration, $plugin_id, $plugin_definition);
-    $this->httpClient = $http_client;
   }
 
   /**
diff --git a/src/Plugin/PdfBackend/PdftkPdfBackend.php b/src/Plugin/PdfBackend/PdftkPdfBackend.php
index a3c401ee1a26fc33b49c0d773a4ad91e51bfcc1c..b28f251ac9643e2089e627189ee52b0a2bb98cc0 100644
--- a/src/Plugin/PdfBackend/PdftkPdfBackend.php
+++ b/src/Plugin/PdfBackend/PdftkPdfBackend.php
@@ -32,27 +32,6 @@ use Symfony\Component\DependencyInjection\ContainerInterface;
  */
 class PdftkPdfBackend extends PdfBackendBase implements ContainerFactoryPluginInterface {
 
-  /**
-   * The file system.
-   *
-   * @var \Drupal\Core\File\FileSystemInterface
-   */
-  protected $fileSystem;
-
-  /**
-   * The FillPDF shell manager.
-   *
-   * @var \Drupal\fillpdf\ShellManager
-   */
-  protected $shellManager;
-
-  /**
-   * The entity type manager.
-   *
-   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
-   */
-  protected $entityTypeManager;
-
   /**
    * Constructs a PdftkPdfBackend plugin object.
    *
@@ -62,18 +41,22 @@ class PdftkPdfBackend extends PdfBackendBase implements ContainerFactoryPluginIn
    *   The plugin_id for the plugin instance.
    * @param array $plugin_definition
    *   The plugin implementation definition.
-   * @param \Drupal\Core\File\FileSystemInterface $file_system
+   * @param \Drupal\Core\File\FileSystemInterface $fileSystem
    *   The file system.
-   * @param \Drupal\fillpdf\ShellManager $shell_manager
+   * @param \Drupal\fillpdf\ShellManager $shellManager
    *   The FillPDF shell manager.
-   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entityTypeManager
    *   The entity type manager.
    */
-  public function __construct(array $configuration, $plugin_id, array $plugin_definition, FileSystemInterface $file_system, ShellManager $shell_manager, EntityTypeManagerInterface $entity_type_manager) {
+  public function __construct(
+    array $configuration,
+    $plugin_id,
+    array $plugin_definition,
+    protected FileSystemInterface $fileSystem,
+    protected ShellManager $shellManager,
+    protected EntityTypeManagerInterface $entityTypeManager,
+  ) {
     parent::__construct($configuration, $plugin_id, $plugin_definition);
-    $this->fileSystem = $file_system;
-    $this->shellManager = $shell_manager;
-    $this->entityTypeManager = $entity_type_manager;
   }
 
   /**
diff --git a/tests/modules/fillpdf_test/src/Plugin/PdfBackend/TestPdfBackend.php b/tests/modules/fillpdf_test/src/Plugin/PdfBackend/TestPdfBackend.php
index 4cb40113731a3a65cd337d008666b0a9a8f7739b..4080623d552c88e47a5eac1f357d97848b321211 100644
--- a/tests/modules/fillpdf_test/src/Plugin/PdfBackend/TestPdfBackend.php
+++ b/tests/modules/fillpdf_test/src/Plugin/PdfBackend/TestPdfBackend.php
@@ -25,13 +25,6 @@ class TestPdfBackend extends PdfBackendBase implements ContainerFactoryPluginInt
    */
   protected $configuration;
 
-  /**
-   * The state.
-   *
-   * @var \Drupal\Core\State\StateInterface
-   */
-  protected $state;
-
   /**
    * Constructs a LocalFillPdfBackend plugin object.
    *
@@ -44,9 +37,13 @@ class TestPdfBackend extends PdfBackendBase implements ContainerFactoryPluginInt
    * @param \Drupal\Core\State\StateInterface $state
    *   The state.
    */
-  public function __construct(array $configuration, $plugin_id, array $plugin_definition, StateInterface $state) {
+  public function __construct(
+    array $configuration,
+    $plugin_id,
+    array $plugin_definition,
+    protected StateInterface $state,
+  ) {
     parent::__construct($configuration, $plugin_id, $plugin_definition);
-    $this->state = $state;
   }
 
   /**