diff --git a/CHANGELOG.md b/CHANGELOG.md
index ff23991..1f72209 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,8 @@ before starting to add changes. Use example [placed in the end of the page](#exa
 
 ## [Unreleased]
 
+- [PR-326](https://github.com/OS2Forms/os2forms/pull/326)
+  Updating ckeditor -> ckeditor5.
 - [PR-322](https://github.com/OS2Forms/os2forms/pull/322)
   Update Digital Post handler error messages.
 - [PR-320](https://github.com/OS2Forms/os2forms/pull/320)
diff --git a/os2forms.info.yml b/os2forms.info.yml
index d08e8e9..d7e530d 100644
--- a/os2forms.info.yml
+++ b/os2forms.info.yml
@@ -5,7 +5,6 @@ package: OS2Forms
 core_version_requirement: ^9 || ^10
 
 dependencies:
-  - 'drupal:ckeditor'
   - 'drupal:editor'
   - 'drupal:entity_print'
   - 'drupal:eu_cookie_compliance'
diff --git a/os2forms.install b/os2forms.install
index b608514..9d1bece 100644
--- a/os2forms.install
+++ b/os2forms.install
@@ -8,6 +8,7 @@
 use Composer\InstalledVersions;
 use Drupal\field\Entity\FieldConfig;
 use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\filter\Entity\FilterFormat;
 use Drupal\taxonomy\Entity\Term;
 use Symfony\Component\Yaml\Yaml;
 
@@ -237,3 +238,30 @@ function os2forms_update_103001() {
 function os2forms_update_103002() {
   \Drupal::service('module_installer')->install(['os2web_key']);
 }
+
+/**
+ * Implements hook_update_N().
+ *
+ * Updating ckeditor -> ckeditor5.
+ */
+function os2forms_update_103003() {
+  \Drupal::service('module_installer')->install(['ckeditor5']);
+
+  $editor_storage = \Drupal::entityTypeManager()->getStorage('editor');
+  /** @var \Drupal\ckeditor5\SmartDefaultSettings $smart_defaults */
+  $smart_defaults = \Drupal::service('ckeditor5.smart_default_settings');
+
+  foreach (FilterFormat::loadMultiple() as $format) {
+    /** @var \Drupal\editor\EditorInterface $editor */
+    $editor = $editor_storage->load($format->id());
+    if (!$editor || $editor->getEditor() !== 'ckeditor') {
+      continue;
+    }
+
+    [$new_editor] = $smart_defaults
+      ->computeSmartDefaultSettings($editor, $format);
+    $new_editor->save();
+  }
+
+  \Drupal::service('module_installer')->uninstall(['ckeditor']);
+}