diff --git a/core/modules/basic_auth/src/Tests/BasicAuthTestTrait.php b/core/modules/basic_auth/src/Tests/BasicAuthTestTrait.php
index c397f63..c21547a 100644
--- a/core/modules/basic_auth/src/Tests/BasicAuthTestTrait.php
+++ b/core/modules/basic_auth/src/Tests/BasicAuthTestTrait.php
@@ -5,9 +5,12 @@
 /**
  * Provides common functionality for Basic Authentication test classes.
  *
- * @deprecated Scheduled for removal in Drupal 9.0.0.
+ * @deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0.
  *   Use \Drupal\Tests\basic_auth\Traits\BasicAuthTestTrait instead.
+ *
+ * @see https://www.drupal.org/node/2862800
  */
+@trigger_error(__FILE__ . ' is deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0. Use \Drupal\Tests\basic_auth\Traits\BasicAuthTestTrait instead. See https://www.drupal.org/node/2862800.', E_USER_DEPRECATED);
 trait BasicAuthTestTrait {
 
   /**