diff -u b/core/modules/filter/tests/src/FunctionalJavascript/FilterHtmlTest.php b/core/modules/filter/tests/src/FunctionalJavascript/FilterHtmlTest.php
--- b/core/modules/filter/tests/src/FunctionalJavascript/FilterHtmlTest.php
+++ b/core/modules/filter/tests/src/FunctionalJavascript/FilterHtmlTest.php
@@ -16,7 +16,7 @@
   /**
    * {@inheritdoc}
    */
-  protected static $modules = ['ckeditor', 'editor', 'filter'];
+  protected static $modules = ['ckeditor5', 'editor', 'filter'];
 
   /**
    * {@inheritdoc}
@@ -60,9 +60,9 @@
       'name' => 'Some HTML',
       'filters' => [
         'filter_html' => [
-          'status' => 1,
+          'status' => TRUE,
           'settings' => [
-            'allowed_html' => '<span class>',
+            'allowed_html' => '<br> <p> <span class> <em> <a href class>',
           ],
         ],
       ],
@@ -70,11 +70,29 @@
 
     Editor::create([
       'format' => 'some_html',
-      'editor' => 'ckeditor',
+      'editor' => 'ckeditor5',
       'settings' => [
+        'toolbar' => [
+          'items' => [
+            'sourceEditing',
+            'link',
+            'italic',
+            'style',
+          ],
+        ],
         'plugins' => [
-          'stylescombo' => [
-            'styles' => 'span.hello-world|Hello World',
+          'ckeditor5_style' => [
+            'styles' => [
+              [
+                'label' => 'Hello World',
+                'element' => '<span class="hello-world">',
+              ],
+            ],
+          ],
+          'ckeditor5_sourceEditing' => [
+            'allowed_tags' => [
+              '<span class>',
+            ],
           ],
         ],
       ],
@@ -83,8 +101,7 @@
     $this->drupalLogin($this->drupalCreateUser(['administer filters']));
     $this->drupalGet('admin/config/content/formats/manage/some_html');
 
-    $js_condition = "jQuery('#edit-filters-filter-html-settings-allowed-html').val() === \"<span class> <strong> <em> <a href> <ul> <li> <ol> <blockquote> <img src alt data-entity-type data-entity-uuid>\"";
-
+    $js_condition = "jQuery('#edit-filters-filter-html-settings-allowed-html').val() === \"<br> <p> <span class> <em> <a href class>\"";
     $this->assertJsCondition($js_condition);
   }