diff --git a/core/modules/simpletest/simpletest.api.php b/core/modules/simpletest/simpletest.api.php
index f911701cb4..45c6da6fdb 100644
--- a/core/modules/simpletest/simpletest.api.php
+++ b/core/modules/simpletest/simpletest.api.php
@@ -30,14 +30,11 @@ function hook_simpletest_alter(&$groups) {
  *
  * This hook is called just once at the beginning of a test group.
  *
- * This hook is only invoked by the Simpletest UI builder. It will not be
+ * This hook is only invoked by the Simpletest UI form runner. It will not be
  * invoked by run-tests.sh or the phpunit tool.
  *
- * @deprecated in Drupal 8.4.x and will be removed before Drupal 9.0.0. Convert
+ * @deprecated in Drupal 8.5.x and will be removed before Drupal 9.0.0. Convert
  *   your test to a PHPUnit-based one and implement test listeners.
- *
- * @todo Modify all invocations of this hook to throw a deprecation error after
- *       https://www.drupal.org/node/2866779
  */
 function hook_test_group_started() {
 }
@@ -47,14 +44,11 @@ function hook_test_group_started() {
  *
  * This hook is called just once at the end of a test group.
  *
- * This hook is only invoked by the Simpletest UI builder. It will not be
+ * This hook is only invoked by the Simpletest UI form runner. It will not be
  * invoked by run-tests.sh or the phpunit tool.
  *
- * @deprecated in Drupal 8.4.x and will be removed before Drupal 9.0.0. Convert
+ * @deprecated in Drupal 8.5.x and will be removed before Drupal 9.0.0. Convert
  *   your test to a PHPUnit-based one and implement test listeners.
- *
- * @todo Modify all invocations of this hook to throw a deprecation error after
- *       https://www.drupal.org/node/2866779
  */
 function hook_test_group_finished() {
 }
@@ -64,7 +58,7 @@ function hook_test_group_finished() {
  *
  * This hook is called when an individual test has finished.
  *
- * This hook is only invoked by the Simpletest UI builder. It will not be
+ * This hook is only invoked by the Simpletest UI form runner. It will not be
  * invoked by run-tests.sh or the phpunit tool.
  *
  * @param
@@ -73,11 +67,8 @@ function hook_test_group_finished() {
  *
  * @see \Drupal\simpletest\WebTestBase::results()
  *
- * @deprecated in Drupal 8.4.x and will be removed before Drupal 9.0.0. Convert
+ * @deprecated in Drupal 8.5.x and will be removed before Drupal 9.0.0. Convert
  *   your test to a PHPUnit-based one and implement test listeners.
- *
- * @todo Modify all invocations of this hook to throw a deprecation error after
- *       https://www.drupal.org/node/2866779
  */
 function hook_test_finished($results) {
 }
diff --git a/core/modules/simpletest/simpletest.module b/core/modules/simpletest/simpletest.module
index 0e0ea2afd4..9f4a1ad4cd 100644
--- a/core/modules/simpletest/simpletest.module
+++ b/core/modules/simpletest/simpletest.module
@@ -161,7 +161,7 @@ function simpletest_run_tests($test_list) {
   ];
   batch_set($batch);
 
-  \Drupal::moduleHandler()->invokeAll('test_group_started');
+  \Drupal::moduleHandler()->invokeAllDeprecated('Convert your test to a PHPUnit-based one and implement test listeners.', 'test_group_started');
 
   return $test_id;
 }
@@ -428,7 +428,7 @@ function _simpletest_batch_operation($test_list_init, $test_id, &$context) {
   else {
     $test = new $test_class($test_id);
     $test->run();
-    \Drupal::moduleHandler()->invokeAll('test_finished', [$test->results]);
+    \Drupal::moduleHandler()->invokeAllDeprecated('Convert your test to a PHPUnit-based one and implement test listeners.', 'test_finished', [$test->results]);
     $test_results[$test_class] = $test->results;
   }
   $size = count($test_list);
@@ -490,7 +490,7 @@ function _simpletest_batch_finished($success, $results, $operations, $elapsed) {
     drupal_set_message(t('The test run did not successfully finish.'), 'error');
     drupal_set_message(t('Use the <em>Clean environment</em> button to clean-up temporary files and tables.'), 'warning');
   }
-  \Drupal::moduleHandler()->invokeAll('test_group_finished');
+  \Drupal::moduleHandler()->invokeAllDeprecated('Convert your test to a PHPUnit-based one and implement test listeners.', 'test_group_finished');
 }
 
 /**