diff --git a/core/modules/comment/src/Plugin/Field/FieldType/CommentItem.php b/core/modules/comment/src/Plugin/Field/FieldType/CommentItem.php
index ff0f5ac..9632c18 100644
--- a/core/modules/comment/src/Plugin/Field/FieldType/CommentItem.php
+++ b/core/modules/comment/src/Plugin/Field/FieldType/CommentItem.php
@@ -116,7 +116,7 @@ public function fieldSettingsForm(array $form, FormStateInterface $form_state) {
     $element['thread_depth'] = [
       '#type' => 'number',
       '#title' => $this->t('Thread depth limit'),
-      '#default_value' => ($settings['thread_depth']) ? $settings['thread_depth'] : CommentManagerInterface::COMMENT_MAX_THREAD_DEPTH,
+      '#default_value' => $settings['thread_depth'],
       '#description' => $this->t('Define comment thread depth.'),
       '#required' => TRUE,
       '#min' => 1,
diff --git a/core/modules/comment/tests/src/Functional/Update/CommentUpdateTest.php b/core/modules/comment/tests/src/Functional/Update/CommentUpdateTest.php
index 9db1221..374fd75 100644
--- a/core/modules/comment/tests/src/Functional/Update/CommentUpdateTest.php
+++ b/core/modules/comment/tests/src/Functional/Update/CommentUpdateTest.php
@@ -78,10 +78,14 @@ public function testPublishedEntityKey() {
    * @see comment_update_8500()
    */
   public function testCommentUpdate8500() {
+    // Grab all existing comment field configs.
     $entity_query = \Drupal::entityQuery('field_config');
     $entity_query->condition('field_type', 'comment');
     $results = $entity_query->execute();
 
+    // Confirm there are existing comment field configs.
+    $this->assertNotEmpty($results, t('Unable to grab existing comment field configs or none exist.'));
+
     // Check that none of the existing comment fields have the thread_depth setting.
     /** @var \Drupal\field\FieldConfigStorage $field_config_storage */
     $field_config_storage = \Drupal::entityTypeManager()->getStorage('field_config');
@@ -94,10 +98,14 @@ public function testCommentUpdate8500() {
     // Run updates.
     $this->runUpdates();
 
+    // Grab all existing comment field configs.
     $entity_query = \Drupal::entityQuery('field_config');
     $entity_query->condition('field_type', 'comment');
     $results = $entity_query->execute();
 
+    // Confirm there are existing comment field configs.
+    $this->assertNotEmpty($results, t('Unable to grab existing comment field configs or none exist.'));
+
     // Check that all existing comment fields have the thread_depth setting after the update.
     /** @var \Drupal\field\FieldConfigStorage $field_config_storage */
     $field_config_storage = \Drupal::entityTypeManager()->getStorage('field_config');