diff --git a/dropzonejs.module b/dropzonejs.module
index 26127d1..f79d578 100644
--- a/dropzonejs.module
+++ b/dropzonejs.module
@@ -42,7 +42,7 @@ function dropzonejs_theme() {
  *   An associative array containing:
  *   - element: A render element representing the file.
  */
-function template_preprocess_dropzonejs(&$variables) {
+function template_preprocess_dropzonejs(array &$variables) {
   $element = $variables['element'];
 
   $variables['attributes'] = [];
diff --git a/js/dropzone.integration.js b/js/dropzone.integration.js
index 518cabf..38fd252 100644
--- a/js/dropzone.integration.js
+++ b/js/dropzone.integration.js
@@ -1,11 +1,10 @@
 /**
- * @file dropzone.integration.js
+ * @file
+ * dropzone.integration.js
  *
  * Defines the behaviors needed for dropzonejs integration.
- *
- * @todo Implement maxfilesexceeded.
- *
  */
+
 (function ($, Drupal, drupalSettings) {
   'use strict';
 
@@ -96,5 +95,4 @@
     }
   };
 
-
 }(jQuery, Drupal, drupalSettings));
diff --git a/modules/eb_widget/js/dropzonejs_eb_widget.common.js b/modules/eb_widget/js/dropzonejs_eb_widget.common.js
index 5c8bf92..1149953 100644
--- a/modules/eb_widget/js/dropzonejs_eb_widget.common.js
+++ b/modules/eb_widget/js/dropzonejs_eb_widget.common.js
@@ -1,8 +1,10 @@
 /**
- * @file dropzonejs_eb_widget.common.js
+ * @file
+ * dropzonejs_eb_widget.common.js
  *
  * Bundles various dropzone eb widget behaviours.
  */
+
 (function ($, Drupal, drupalSettings) {
   'use strict';
 
diff --git a/modules/eb_widget/js/dropzonejs_eb_widget.ief_edit.js b/modules/eb_widget/js/dropzonejs_eb_widget.ief_edit.js
index 7a1ee7e..7ae974b 100644
--- a/modules/eb_widget/js/dropzonejs_eb_widget.ief_edit.js
+++ b/modules/eb_widget/js/dropzonejs_eb_widget.ief_edit.js
@@ -1,8 +1,10 @@
 /**
- * @file dropzonejs_eb_widget.common.js
+ * @file
+ * dropzonejs_eb_widget.ief_edit.js
  *
  * Bundles various dropzone eb widget behaviours.
  */
+
 (function ($, Drupal, drupalSettings) {
   'use strict';
 
diff --git a/modules/eb_widget/src/Plugin/EntityBrowser/Widget/DropzoneJsEbWidget.php b/modules/eb_widget/src/Plugin/EntityBrowser/Widget/DropzoneJsEbWidget.php
index 0572d15..ed68a17 100644
--- a/modules/eb_widget/src/Plugin/EntityBrowser/Widget/DropzoneJsEbWidget.php
+++ b/modules/eb_widget/src/Plugin/EntityBrowser/Widget/DropzoneJsEbWidget.php
@@ -98,7 +98,7 @@ public static function create(ContainerInterface $container, array $configuratio
   public function defaultConfiguration() {
     return [
       'upload_location' => 'public://[date:custom:Y]-[date:custom:m]',
-      'dropzone_description' => t('Drop files here to upload them'),
+      'dropzone_description' => $this->t('Drop files here to upload them'),
       'max_filesize' => file_upload_max_size() / pow(Bytes::KILOBYTE, 2) . 'M',
       'extensions' => 'jpg jpeg gif png txt doc xls pdf ppt pps odt ods odp',
     ] + parent::defaultConfiguration();
@@ -117,7 +117,7 @@ public function getForm(array &$original_form, FormStateInterface $form_state, a
     }
     $config = $this->getConfiguration();
     $form['upload'] = [
-      '#title' => t('File upload'),
+      '#title' => $this->t('File upload'),
       '#type' => 'dropzonejs',
       '#required' => TRUE,
       '#dropzone_description' => $config['settings']['dropzone_description'],
@@ -206,17 +206,17 @@ public function validate(array &$form, FormStateInterface $form_state) {
     if ($trigger['#type'] == 'submit' && $trigger['#name'] == 'op') {
       $upload_location = $this->getUploadLocation();
       if (!file_prepare_directory($upload_location, FILE_CREATE_DIRECTORY | FILE_MODIFY_PERMISSIONS)) {
-        $form_state->setError($form['widget']['upload'], t('Files could not be uploaded because the destination directory %destination is not configured correctly.', ['%destination' => $this->getConfiguration()['settings']['upload_location']]));
+        $form_state->setError($form['widget']['upload'], $this->t('Files could not be uploaded because the destination directory %destination is not configured correctly.', ['%destination' => $this->getConfiguration()['settings']['upload_location']]));
       }
 
       $files = $this->getFiles($form, $form_state);
       if (in_array(FALSE, $files)) {
         // @todo Output the actual errors from validateFile.
-        $form_state->setError($form['widget']['upload'], t('Some files that you are trying to upload did not pass validation. Requirements are: max file %size, allowed extensions are %extensions', ['%size' => $this->getConfiguration()['settings']['max_filesize'], '%extensions' => $this->getConfiguration()['settings']['extensions']]));
+        $form_state->setError($form['widget']['upload'], $this->t('Some files that you are trying to upload did not pass validation. Requirements are: max file %size, allowed extensions are %extensions', ['%size' => $this->getConfiguration()['settings']['max_filesize'], '%extensions' => $this->getConfiguration()['settings']['extensions']]));
       }
 
       if (empty($files)) {
-        $form_state->setError($form['widget']['upload'], t('At least one valid file should be uploaded.'));
+        $form_state->setError($form['widget']['upload'], $this->t('At least one valid file should be uploaded.'));
       }
 
       // If there weren't any errors set, run the normal validators.
diff --git a/modules/eb_widget/src/Plugin/EntityBrowser/Widget/InlineEntityFormMediaWidget.php b/modules/eb_widget/src/Plugin/EntityBrowser/Widget/InlineEntityFormMediaWidget.php
index 3b2ecbc..083d1f9 100644
--- a/modules/eb_widget/src/Plugin/EntityBrowser/Widget/InlineEntityFormMediaWidget.php
+++ b/modules/eb_widget/src/Plugin/EntityBrowser/Widget/InlineEntityFormMediaWidget.php
@@ -139,7 +139,7 @@ public function validate(array &$form, FormStateInterface $form_state) {
    * @return \Drupal\media_entity\MediaInterface[]
    *   The prepared media entities.
    */
-  protected function prepareEntitiesFromForm($form, FormStateInterface $form_state) {
+  protected function prepareEntitiesFromForm(array $form, FormStateInterface $form_state) {
     $media_entities = [];
     foreach (Element::children($form['widget']['entities']) as $key) {
       /** @var \Drupal\Core\Entity\ContentEntityInterface $entity */
diff --git a/src/DropzoneJsUploadSave.php b/src/DropzoneJsUploadSave.php
index 8d72b19..cd0d188 100644
--- a/src/DropzoneJsUploadSave.php
+++ b/src/DropzoneJsUploadSave.php
@@ -101,7 +101,7 @@ public function __construct(EntityTypeManagerInterface $entity_type_manager, Mim
   /**
    * {@inheritdoc}
    */
-  public function createFile($uri, $destination, $extensions, AccountProxyInterface $user, $validators = []) {
+  public function createFile($uri, $destination, $extensions, AccountProxyInterface $user, array $validators = []) {
     // Create the file entity.
     $uri = file_stream_wrapper_uri_normalize($uri);
     $file_info = new \SplFileInfo($uri);
diff --git a/src/DropzoneJsUploadSaveInterface.php b/src/DropzoneJsUploadSaveInterface.php
index f349439..9d5672c 100644
--- a/src/DropzoneJsUploadSaveInterface.php
+++ b/src/DropzoneJsUploadSaveInterface.php
@@ -35,14 +35,14 @@ interface DropzoneJsUploadSaveInterface {
    *   The file entity of the newly uploaded file or false in case of a failure.
    *   The file isn't saved yet. That should be handled by the caller.
    */
-  public function createFile($uri, $destination, $extensions, AccountProxyInterface $user, $validators = []);
+  public function createFile($uri, $destination, $extensions, AccountProxyInterface $user, array $validators = []);
 
   /**
    * Validate the uploaded file.
    *
    * @param \Drupal\file\FileInterface $file
    *   The file entity object.
-   * @param array $extensions
+   * @param string $extensions
    *   A space separated string of valid extensions.
    * @param array $additional_validators
    *   An optional, associative array of callback functions used to validate the
diff --git a/src/Element/DropzoneJs.php b/src/Element/DropzoneJs.php
index ae05c1f..ba48de5 100644
--- a/src/Element/DropzoneJs.php
+++ b/src/Element/DropzoneJs.php
@@ -104,7 +104,7 @@ public static function processDropzoneJs(&$element, FormStateInterface $form_sta
    * @return array
    *   The $element with prepared variables ready for input.html.twig.
    */
-  public static function preRenderDropzoneJs($element) {
+  public static function preRenderDropzoneJs(array $element) {
     // Convert the human size input to bytes, convert it to MB and round it.
     $max_size = round(Bytes::toInt($element['#max_filesize']) / pow(Bytes::KILOBYTE, 2), 2);
 
@@ -183,7 +183,7 @@ public static function valueCallback(&$element, $input, FormStateInterface $form
    * @return string
    *   A space separated list of extensions.
    */
-  public static function getValidExtensions($element) {
+  public static function getValidExtensions(array $element) {
     return isset($element['#extensions']) ? $element['#extensions'] : self::DEFAULT_VALID_EXTENSIONS;
   }
 
diff --git a/src/Events/DropzoneMediaEntityCreateEvent.php b/src/Events/DropzoneMediaEntityCreateEvent.php
index a325504..dd545d9 100644
--- a/src/Events/DropzoneMediaEntityCreateEvent.php
+++ b/src/Events/DropzoneMediaEntityCreateEvent.php
@@ -61,7 +61,7 @@ class DropzoneMediaEntityCreateEvent extends Event {
    * @param array $element
    *   The Dropzone form element.
    */
-  public function __construct(MediaInterface $media_entity, FileInterface $file, $form, FormStateInterface $form_state, $element) {
+  public function __construct(MediaInterface $media_entity, FileInterface $file, array $form, FormStateInterface $form_state, array $element) {
     $this->mediaEntity = $media_entity;
     $this->file = $file;
     $this->form = $form;
@@ -145,7 +145,7 @@ public function getElement() {
    * @param array $element
    *   The updated form element.
    */
-  public function setElement($element) {
+  public function setElement(array $element) {
     $this->element = $element;
   }