diff --git a/core/modules/comment/lib/Drupal/comment/CommentFormController.php b/core/modules/comment/lib/Drupal/comment/CommentFormController.php
index e9f0151..8deed69 100644
--- a/core/modules/comment/lib/Drupal/comment/CommentFormController.php
+++ b/core/modules/comment/lib/Drupal/comment/CommentFormController.php
@@ -212,9 +212,7 @@ public function form(array $form, array &$form_state) {
       '#access' => $is_admin,
     );
 
-    $form['subject'] += array(
-      '#access' => $instance->getSetting('subject'),
-    );
+    $form['subject']['#access'] = $instance->getSetting('subject');
     unset($form['subject']['widget'][0]['value']['#description']);
 
     // Used for conditional validation of author fields.
diff --git a/core/modules/comment/lib/Drupal/comment/Tests/CommentBookTest.php b/core/modules/comment/lib/Drupal/comment/Tests/CommentBookTest.php
index 4d92e9d..719a303 100644
--- a/core/modules/comment/lib/Drupal/comment/Tests/CommentBookTest.php
+++ b/core/modules/comment/lib/Drupal/comment/Tests/CommentBookTest.php
@@ -69,7 +69,7 @@ public function testBookCommentPrint() {
     $this->assertText($comment_subject, 'Comment subject found');
     $this->assertText($comment_body, 'Comment body found');
     $this->assertText(t('Add new comment'), 'Comment form found');
-    $this->assertField('subject', 'Comment form subject found');
+    $this->assertField('subject[0][value]', 'Comment form subject found');
 
     $this->drupalGet('book/export/html/' . $book_node->id());
 
diff --git a/core/modules/config_translation/lib/Drupal/config_translation/Tests/ConfigTranslationUiTest.php b/core/modules/config_translation/lib/Drupal/config_translation/Tests/ConfigTranslationUiTest.php
index 9aa1a1c..405aaf5 100644
--- a/core/modules/config_translation/lib/Drupal/config_translation/Tests/ConfigTranslationUiTest.php
+++ b/core/modules/config_translation/lib/Drupal/config_translation/Tests/ConfigTranslationUiTest.php
@@ -299,7 +299,7 @@ public function testContactConfigEntityTranslation() {
 
       // Submit feedback.
       $edit = array(
-        'subject[0][value]' => 'Test subject',
+        'subject' => 'Test subject',
         'message' => 'Test message',
       );
       $this->drupalPostForm(NULL, $edit, t('Send message'));
diff --git a/core/modules/search/lib/Drupal/search/Tests/SearchCommentCountToggleTest.php b/core/modules/search/lib/Drupal/search/Tests/SearchCommentCountToggleTest.php
index 5f77bd0..497173a 100644
--- a/core/modules/search/lib/Drupal/search/Tests/SearchCommentCountToggleTest.php
+++ b/core/modules/search/lib/Drupal/search/Tests/SearchCommentCountToggleTest.php
@@ -61,7 +61,7 @@ function setUp() {
 
     // Create a comment array
     $edit_comment = array();
-    $edit_comment['subject'] = $this->randomName();
+    $edit_comment['subject[0][value]'] = $this->randomName();
     $edit_comment['comment_body[0][value]'] = $this->randomName();
 
     // Post comment to the test node with comment
diff --git a/core/modules/search/lib/Drupal/search/Tests/SearchCommentTest.php b/core/modules/search/lib/Drupal/search/Tests/SearchCommentTest.php
index b470ae6..1b44aa4 100644
--- a/core/modules/search/lib/Drupal/search/Tests/SearchCommentTest.php
+++ b/core/modules/search/lib/Drupal/search/Tests/SearchCommentTest.php
@@ -82,7 +82,7 @@ function testSearchResultsComment() {
     $node = $this->drupalCreateNode(array('type' => 'article'));
     // Post a comment using 'Full HTML' text format.
     $edit_comment = array();
-    $edit_comment['subject'] = 'Test comment subject';
+    $edit_comment['subject[0][value]'] = 'Test comment subject';
     $edit_comment['comment_body[0][value]'] = '<h1>' . $comment_body . '</h1>';
     $full_html_format_id = 'full_html';
     $edit_comment['comment_body[0][format]'] = $full_html_format_id;
@@ -94,12 +94,12 @@ function testSearchResultsComment() {
 
     // Search for the comment subject.
     $edit = array(
-      'search_block_form' => "'" . $edit_comment['subject'] . "'",
+      'search_block_form' => "'" . $edit_comment['subject[0][value]'] . "'",
     );
     $this->drupalPostForm('', $edit, t('Search'));
     $node2 = node_load($node->id(), TRUE);
     $this->assertText($node2->label(), 'Node found in search results.');
-    $this->assertText($edit_comment['subject'], 'Comment subject found in search results.');
+    $this->assertText($edit_comment['subject[0][value]'], 'Comment subject found in search results.');
 
     // Search for the comment body.
     $edit = array(
@@ -145,7 +145,7 @@ function testSearchResultsCommentAccess() {
 
     // Post a comment using 'Full HTML' text format.
     $edit_comment = array();
-    $edit_comment['subject'] = $this->comment_subject;
+    $edit_comment['subject[0][value]'] = $this->comment_subject;
     $edit_comment['comment_body[0][value]'] = '<h1>' . $comment_body . '</h1>';
     $this->drupalPostForm('comment/reply/node/' . $this->node->id() . '/comment', $edit_comment, t('Save'));