diff --git a/core/modules/language/language.install b/core/modules/language/language.install
index fe79067..dcec16a 100644
--- a/core/modules/language/language.install
+++ b/core/modules/language/language.install
@@ -5,36 +5,9 @@
  * Update functions for Language module.
  */
 
-use Drupal\Core\Entity\Entity\EntityFormDisplay;
-
 /**
  * Rebuild the container as services changed.
  */
 function language_update_8001() {
   \Drupal::service('kernel')->invalidateContainer();
 }
-
-/**
- * @addtogroup updates-8.4.0
- * @{
- */
-
-/**
- * Add the 'include_locked' settings to the 'language_select' widget.
- */
-function language_update_8400() {
-  foreach (EntityFormDisplay::loadMultiple() as $display_form) {
-    $content = $display_form->get('content');
-    foreach (array_keys($content) as $element) {
-      if (isset($content[$element]['type']) && $content[$element]['type'] == 'language_select') {
-        $content[$element]['settings'] = ['include_locked' => TRUE];
-        $display_form->set('content', $content);
-        $display_form->save();
-      }
-    }
-  }
-}
-
-/**
- * @} End of "addtogroup updates-8.4.0".
- */
diff --git a/core/modules/language/language.post_update.php b/core/modules/language/language.post_update.php
new file mode 100644
index 0000000..d8ffe64
--- /dev/null
+++ b/core/modules/language/language.post_update.php
@@ -0,0 +1,33 @@
+<?php
+
+/**
+ * @file
+ * Post update functions for Language module.
+ */
+
+use Drupal\Core\Entity\Entity\EntityFormDisplay;
+
+/**
+ * @addtogroup updates-8.4.0
+ * @{
+ */
+
+/**
+ * Add the 'include_locked' settings to the 'language_select' widget.
+ */
+function language_post_update_language_select_widget() {
+  foreach (EntityFormDisplay::loadMultiple() as $display_form) {
+    $content = $display_form->get('content');
+    foreach (array_keys($content) as $element) {
+      if (isset($content[$element]['type']) && $content[$element]['type'] == 'language_select') {
+        $content[$element]['settings'] = ['include_locked' => TRUE];
+        $display_form->set('content', $content);
+        $display_form->save();
+      }
+    }
+  }
+}
+
+/**
+ * @} End of "addtogroup updates-8.4.0".
+ */
diff --git a/core/modules/language/src/Tests/Update/LanguageSelectWidgetUpdateTest.php b/core/modules/language/src/Tests/Update/LanguageSelectWidgetUpdateTest.php
index 05782d7..392b51b 100644
--- a/core/modules/language/src/Tests/Update/LanguageSelectWidgetUpdateTest.php
+++ b/core/modules/language/src/Tests/Update/LanguageSelectWidgetUpdateTest.php
@@ -22,9 +22,9 @@ protected function setDatabaseDumpFiles() {
   }
 
   /**
-   * Tests that language_select widgets are updated.
+   * Tests language_post_update_language_select_widget().
    */
-  public function testLanguageUpdate8401() {
+  public function testLanguagePostUpdateLanguageSelectWidget() {
     // Tests before the update.
     $this->doTestLanguageSelectWidgets([]);