.../tests/src/Kernel/ConfigurablePluginTest.php    | 18 +++++++++
 .../tests/src/Kernel/SmartDefaultSettingsTest.php  | 39 ++++++++++++++++++-
 .../config/install/editor.editor.full_html.yml     | 44 ++++++++++++++++++++++
 3 files changed, 100 insertions(+), 1 deletion(-)

diff --git a/core/modules/ckeditor5/tests/src/Kernel/ConfigurablePluginTest.php b/core/modules/ckeditor5/tests/src/Kernel/ConfigurablePluginTest.php
index a786cb4332..f12a23ce61 100644
--- a/core/modules/ckeditor5/tests/src/Kernel/ConfigurablePluginTest.php
+++ b/core/modules/ckeditor5/tests/src/Kernel/ConfigurablePluginTest.php
@@ -70,6 +70,24 @@ public function testDefaults() {
       'ckeditor5_sourceEditing' => [
         'allowed_tags' => [],
       ],
+      'ckeditor5_codeBlock' => [
+        'languages' => [
+          ['language' => 'plaintext', 'label' => 'Plain text'],
+          ['language' => 'c', 'label' => 'C'],
+          ['language' => 'cs', 'label' => 'C#'],
+          ['language' => 'cpp', 'label' => 'C++'],
+          ['language' => 'css', 'label' => 'CSS'],
+          ['language' => 'diff', 'label' => 'Diff'],
+          ['language' => 'html', 'label' => 'HTML'],
+          ['language' => 'java', 'label' => 'Java'],
+          ['language' => 'javascript', 'label' => 'JavaScript'],
+          ['language' => 'php', 'label' => 'PHP'],
+          ['language' => 'python', 'label' => 'Python'],
+          ['language' => 'ruby', 'label' => 'Ruby'],
+          ['language' => 'typescript', 'label' => 'TypeScript'],
+          ['language' => 'xml', 'label' => 'XML'],
+        ],
+      ],
       'ckeditor5_list' => [
         'reversed' => TRUE,
         'startIndex' => TRUE,
diff --git a/core/modules/ckeditor5/tests/src/Kernel/SmartDefaultSettingsTest.php b/core/modules/ckeditor5/tests/src/Kernel/SmartDefaultSettingsTest.php
index 4508759f83..bf294d8375 100644
--- a/core/modules/ckeditor5/tests/src/Kernel/SmartDefaultSettingsTest.php
+++ b/core/modules/ckeditor5/tests/src/Kernel/SmartDefaultSettingsTest.php
@@ -903,7 +903,26 @@ public function provider() {
             ['codeBlock'],
           ),
         ],
-        'plugins' => $basic_html_test_case['expected_ckeditor5_settings']['plugins'],
+        'plugins' => [
+          'ckeditor5_codeBlock' => [
+            'languages' => [
+              ['label' => 'Plain text', 'language' => 'plaintext'],
+              ['label' => 'C', 'language' => 'c'],
+              ['label' => 'C#', 'language' => 'cs'],
+              ['label' => 'C++', 'language' => 'cpp'],
+              ['label' => 'CSS', 'language' => 'css'],
+              ['label' => 'Diff', 'language' => 'diff'],
+              ['label' => 'HTML', 'language' => 'html'],
+              ['label' => 'Java', 'language' => 'java'],
+              ['label' => 'JavaScript', 'language' => 'javascript'],
+              ['label' => 'PHP', 'language' => 'php'],
+              ['label' => 'Python', 'language' => 'python'],
+              ['label' => 'Ruby', 'language' => 'ruby'],
+              ['label' => 'TypeScript', 'language' => 'typescript'],
+              ['label' => 'XML', 'language' => 'xml'],
+            ],
+          ],
+        ] + $basic_html_test_case['expected_ckeditor5_settings']['plugins'],
       ],
       'expected_superset' => '<code class="language-*">',
       'expected_fundamental_compatibility_violations' => $basic_html_test_case['expected_fundamental_compatibility_violations'],
@@ -1215,6 +1234,24 @@ public function provider() {
           ],
         ],
         'plugins' => [
+          'ckeditor5_codeBlock' => [
+            'languages' => [
+              ['label' => 'Plain text', 'language' => 'plaintext'],
+              ['label' => 'C', 'language' => 'c'],
+              ['label' => 'C#', 'language' => 'cs'],
+              ['label' => 'C++', 'language' => 'cpp'],
+              ['label' => 'CSS', 'language' => 'css'],
+              ['label' => 'Diff', 'language' => 'diff'],
+              ['label' => 'HTML', 'language' => 'html'],
+              ['label' => 'Java', 'language' => 'java'],
+              ['label' => 'JavaScript', 'language' => 'javascript'],
+              ['label' => 'PHP', 'language' => 'php'],
+              ['label' => 'Python', 'language' => 'python'],
+              ['label' => 'Ruby', 'language' => 'ruby'],
+              ['label' => 'TypeScript', 'language' => 'typescript'],
+              ['label' => 'XML', 'language' => 'xml'],
+            ],
+          ],
           'ckeditor5_heading' => [
             'enabled_headings' => [
               'heading2',
diff --git a/core/profiles/standard/config/install/editor.editor.full_html.yml b/core/profiles/standard/config/install/editor.editor.full_html.yml
index babf6b59e0..7904ed2a4f 100644
--- a/core/profiles/standard/config/install/editor.editor.full_html.yml
+++ b/core/profiles/standard/config/install/editor.editor.full_html.yml
@@ -46,6 +46,50 @@ settings:
       startIndex: true
     ckeditor5_sourceEditing:
       allowed_tags: {  }
+    ckeditor5_codeBlock:
+      languages:
+        -
+          label: 'Plain text'
+          language: plaintext
+        -
+          label: C
+          language: c
+        -
+          label: 'C#'
+          language: cs
+        -
+          label: C++
+          language: cpp
+        -
+          label: CSS
+          language: css
+        -
+          label: Diff
+          language: diff
+        -
+          label: HTML
+          language: html
+        -
+          label: Java
+          language: java
+        -
+          label: JavaScript
+          language: javascript
+        -
+          label: PHP
+          language: php
+        -
+          label: Python
+          language: python
+        -
+          label: Ruby
+          language: ruby
+        -
+          label: TypeScript
+          language: typescript
+        -
+          label: XML
+          language: xml
 image_upload:
   status: true
   scheme: public