diff --git a/core/modules/locale/locale.pages.inc b/core/modules/locale/locale.pages.inc
index d8d7659bf9ca8859e22a1abf7707df89b2a7f936..2f8957cc88149296683bcf03664701b49d69aa56 100644
--- a/core/modules/locale/locale.pages.inc
+++ b/core/modules/locale/locale.pages.inc
@@ -13,9 +13,14 @@
  *
  * Manually checks the translation status without the use of cron.
  *
- * @see locale_menu()
+ * @deprecated in Drupal 8.5.0 and will be removed before 9.0.0. It is unused by
+ *   Drupal core. Duplicate this function in your own extension if you need its
+ *   behavior.
+ *
+ * @see https://www.drupal.org/node/2931188
  */
 function locale_translation_manual_status() {
+  @trigger_error('locale_translation_manual_status() is deprecated in Drupal 8.5.0 and will be removed before Drupal 9.0.0. It is unused by Drupal core. Duplicate this function in your own extension if you need its behavior.', E_USER_DEPRECATED);
   module_load_include('compare.inc', 'locale');
 
   // Check the translation status of all translatable projects in all languages.
diff --git a/core/modules/locale/tests/src/Kernel/LocaleDeprecationsTest.php b/core/modules/locale/tests/src/Kernel/LocaleDeprecationsTest.php
new file mode 100644
index 0000000000000000000000000000000000000000..b98bc0552a7a4f90566f8271e2a1f198a88bff7e
--- /dev/null
+++ b/core/modules/locale/tests/src/Kernel/LocaleDeprecationsTest.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace Drupal\Tests\locale\Kernel;
+
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * Tests deprecations in the locale module.
+ *
+ * @group locale
+ * @group legacy
+ */
+class LocaleDeprecationsTest extends KernelTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = ['locale', 'system'];
+
+  /**
+   * @expectedDeprecation locale_translation_manual_status() is deprecated in Drupal 8.5.0 and will be removed before Drupal 9.0.0. It is unused by Drupal core. Duplicate this function in your own extension if you need its behavior.
+   */
+  public function testLocaleTranslationManualStatusDeprecation() {
+    module_load_include('pages.inc', 'locale');
+    $this->assertNotNull(\locale_translation_manual_status());
+  }
+
+}