diff --git a/CHANGELOG.md b/CHANGELOG.md
index d15a292c..f85c82ce 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,12 @@ before starting to add changes. Use example [placed in the end of the page](#exa
 
 ## [Unreleased]
 
+## [3.15.1] 2024-05-14
+
+- Added missing return type.
+- Added new webform submission storage class to handle enable both encryption
+  and revision at the same time.
+
 ## [3.15.0] 2024-05-03
 
 - Added webform encryption modules
@@ -218,7 +224,8 @@ before starting to add changes. Use example [placed in the end of the page](#exa
 - Security in case of vulnerabilities.
 ```
 
-[Unreleased]: https://github.com/OS2Forms/os2forms/compare/3.15.0...HEAD
+[Unreleased]: https://github.com/OS2Forms/os2forms/compare/3.15.1...HEAD
+[3.15.1]: https://github.com/OS2Forms/os2forms/compare/3.15.0...3.15.1
 [3.15.0]: https://github.com/OS2Forms/os2forms/compare/3.14.1...3.15.0
 [3.14.1]: https://github.com/OS2Forms/os2forms/compare/3.14.0...3.14.1
 [3.14.0]: https://github.com/OS2Forms/os2forms/compare/3.13.3...3.14.0
diff --git a/modules/os2forms_encrypt/os2forms_encrypt.install b/modules/os2forms_encrypt/os2forms_encrypt.install
new file mode 100644
index 00000000..0a42e4ee
--- /dev/null
+++ b/modules/os2forms_encrypt/os2forms_encrypt.install
@@ -0,0 +1,19 @@
+<?php
+
+/**
+ * @file
+ * This module enabled webform submission encryption as a default option.
+ */
+
+/**
+ * Implements hook_install().
+ *
+ * We need to change the modules weight to ensure that our webform_submission
+ * class is used and thereby overriding the webform_encrypt and webform_revision
+ * classes.
+ *
+ * The class is set in os2forms_encrypt_entity_type_alter().
+ */
+function os2forms_encrypt_install() {
+  module_set_weight('os2forms_encrypt', 9999);
+}
diff --git a/modules/os2forms_encrypt/os2forms_encrypt.module b/modules/os2forms_encrypt/os2forms_encrypt.module
index daef0b2d..516a7fe4 100644
--- a/modules/os2forms_encrypt/os2forms_encrypt.module
+++ b/modules/os2forms_encrypt/os2forms_encrypt.module
@@ -21,3 +21,15 @@ function os2forms_encrypt_element_info_alter(array &$definitions): void {
     }
   }
 }
+
+/**
+ * Implements hook_entity_type_alter().
+ *
+ * Override webform submission class to enable encryption and revision.
+ */
+function os2forms_encrypt_entity_type_alter(array &$entity_types): void {
+  /** @var \Drupal\Core\Entity\EntityTypeInterface[] $entity_types */
+  if (isset($entity_types['webform_submission'])) {
+    $entity_types['webform_submission']->setStorageClass('Drupal\os2forms_encrypt\WebformOs2FormsEncryptSubmissionStorage');
+  }
+}
diff --git a/modules/os2forms_encrypt/src/WebformOs2FormsEncryptSubmissionStorage.php b/modules/os2forms_encrypt/src/WebformOs2FormsEncryptSubmissionStorage.php
new file mode 100644
index 00000000..ac02e348
--- /dev/null
+++ b/modules/os2forms_encrypt/src/WebformOs2FormsEncryptSubmissionStorage.php
@@ -0,0 +1,175 @@
+<?php
+
+namespace Drupal\os2forms_encrypt;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Session\AccountInterface;
+use Drupal\webform\WebformInterface;
+use Drupal\webform_encrypt\WebformEncryptSubmissionStorage;
+use Drupal\webform_revisions\Controller\WebformRevisionsController;
+
+/**
+ * This class extension WebformEncryptSubmissionStorage.
+ *
+ * This is to enabled encryption and decryption for data and checks if webform
+ * revisions are enabled and runs the same code (copied here as multiple
+ * inherits is not a thing in PHP).
+ *
+ * So the getColumns is an moduleExists check and the rest is copied from
+ * webform revision storage class.
+ */
+class WebformOs2FormsEncryptSubmissionStorage extends WebformEncryptSubmissionStorage {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getColumns(WebformInterface $webform = NULL, EntityInterface $source_entity = NULL, AccountInterface $account = NULL, $include_elements = TRUE) {
+    if (!\Drupal::moduleHandler()->moduleExists('webform_revisions')) {
+      return parent::getColumns($webform, $source_entity, $account, $include_elements);
+    }
+    else {
+      $view_any = $webform && $webform->access('submission_view_any');
+
+      $columns = [];
+
+      // Serial number.
+      $columns['serial'] = [
+        'title' => $this->t('#'),
+      ];
+
+      // Submission ID.
+      $columns['sid'] = [
+        'title' => $this->t('SID'),
+      ];
+
+      // Submission label.
+      $columns['label'] = [
+        'title' => $this->t('Submission title'),
+        'sort' => FALSE,
+      ];
+
+      // UUID.
+      $columns['uuid'] = [
+        'title' => $this->t('UUID'),
+      ];
+
+      // Draft.
+      $columns['in_draft'] = [
+        'title' => $this->t('In draft'),
+      ];
+
+      if (empty($account)) {
+        // Sticky (Starred/Unstarred).
+        $columns['sticky'] = [
+          'title' => $this->t('Starred'),
+        ];
+
+        // Locked.
+        $columns['locked'] = [
+          'title' => $this->t('Locked'),
+        ];
+
+        // Notes.
+        $columns['notes'] = [
+          'title' => $this->t('Notes'),
+        ];
+      }
+
+      // Created.
+      $columns['created'] = [
+        'title' => $this->t('Created'),
+      ];
+
+      // Completed.
+      $columns['completed'] = [
+        'title' => $this->t('Completed'),
+      ];
+
+      // Changed.
+      $columns['changed'] = [
+        'title' => $this->t('Changed'),
+      ];
+
+      // Source entity.
+      if ($view_any && empty($source_entity)) {
+        $columns['entity'] = [
+          'title' => $this->t('Submitted to'),
+          'sort' => FALSE,
+        ];
+      }
+
+      // Submitted by.
+      if (empty($account)) {
+        $columns['uid'] = [
+          'title' => $this->t('User'),
+        ];
+      }
+
+      // Submission language.
+      if ($view_any && \Drupal::moduleHandler()->moduleExists('language')) {
+        $columns['langcode'] = [
+          'title' => $this->t('Language'),
+        ];
+      }
+
+      // Remote address.
+      $columns['remote_addr'] = [
+        'title' => $this->t('IP address'),
+      ];
+
+      // Webform and source entity for entity.webform_submission.collection.
+      // @see /admin/structure/webform/submissions/manage
+      if (empty($webform) && empty($source_entity)) {
+        $columns['webform_id'] = [
+          'title' => $this->t('Webform'),
+        ];
+        $columns['entity'] = [
+          'title' => $this->t('Submitted to'),
+          'sort' => FALSE,
+        ];
+      }
+
+      // Webform elements.
+      if ($webform && $include_elements) {
+        /** @var \Drupal\webform\Plugin\WebformElementManagerInterface $element_manager */
+        $element_manager = \Drupal::service('plugin.manager.webform.element');
+        $content_entity_id = $webform->getContentEntityID();
+        $revision_ids = $this->database->query(
+          'SELECT revision FROM {config_entity_revisions_revision} WHERE id = :id',
+          [':id' => $content_entity_id]
+        )->fetchCol();
+        if (!$revision_ids) {
+          return parent::getColumns($webform, $source_entity, $account, $include_elements);
+        }
+
+        foreach ($revision_ids as $revision_id) {
+          $revisionController = WebformRevisionsController::create(\Drupal::getContainer());
+          $webform = $revisionController->loadConfigEntityRevision($revision_id, $webform->id());
+          $elements = $webform->getElementsInitializedFlattenedAndHasValue('view');
+          foreach ($elements as $element) {
+            /** @var \Drupal\webform\Plugin\WebformElementInterface $element_plugin */
+            $element_plugin = $element_manager->createInstance($element['#type']);
+            // Replace tokens which can be used in an element's #title.
+            $element_plugin->replaceTokens($element, $webform);
+            $columns += $element_plugin->getTableColumn($element);
+          }
+        }
+      }
+
+      // Operations.
+      $columns['operations'] = [
+        'title' => $this->t('Operations'),
+        'sort' => FALSE,
+      ];
+
+      // Add name and format to all columns.
+      foreach ($columns as $name => &$column) {
+        $column['name'] = $name;
+        $column['format'] = 'value';
+      }
+
+      return $columns;
+    }
+  }
+
+}
diff --git a/modules/os2forms_webform_list/src/CustomWebformEntityListBuilder.php b/modules/os2forms_webform_list/src/CustomWebformEntityListBuilder.php
index 94e64fbb..1eb27312 100644
--- a/modules/os2forms_webform_list/src/CustomWebformEntityListBuilder.php
+++ b/modules/os2forms_webform_list/src/CustomWebformEntityListBuilder.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\os2forms_webform_list;
 
+use Drupal\Core\Entity\Query\QueryInterface;
 use Drupal\webform\WebformEntityListBuilder;
 
 /**
@@ -27,7 +28,7 @@ class CustomWebformEntityListBuilder extends WebformEntityListBuilder {
    * @return \Drupal\Core\Entity\Query\QueryInterface
    *   An entity query.
    */
-  protected function getQuery($keys = '', $category = '', $state = '') {
+  protected function getQuery($keys = '', $category = '', $state = ''): QueryInterface {
     $query = parent::getQuery($keys, $category, $state);
 
     // Setup a required condition for the list builder to respect webform update