diff --git a/core/modules/comment/lib/Drupal/comment/Tests/CommentFieldsTest.php b/core/modules/comment/lib/Drupal/comment/Tests/CommentFieldsTest.php
index 8f34413..66c0397 100644
--- a/core/modules/comment/lib/Drupal/comment/Tests/CommentFieldsTest.php
+++ b/core/modules/comment/lib/Drupal/comment/Tests/CommentFieldsTest.php
@@ -128,4 +128,77 @@ function testCommentFormat() {
     $edit = array('comment_body[0][value]' => $this->randomName(8));
     $this->drupalPostForm('node/' . $this->node->id(), $edit, t('Save'));
   }
+
+  /**
+   * Tests that nothing is broken when adding content and disabling the 
+   * corresponding content type. More info at #1966448.
+   */
+  function testCommentHasFieldDisabledContentType() {
+    // Create user to add forum content.
+    $forum_user = $this->drupalCreateUser(array(
+      'administer modules',
+      'administer forums',
+      'create forum content',
+      'create article content',
+      'access content overview',
+    ));
+
+    $this->drupalLogin($forum_user);
+    
+    // Generate a random name/description.
+    $name = $this->randomName(10);
+    $description = $this->randomName(100);
+
+    $edit = array(
+      'name' => $name,
+      'description[value]' => $description,
+      'weight' => '0',
+    );
+
+    // Create forum.
+    $this->drupalPostForm('admin/structure/forum/add/forum', $edit, t('Save'));
+    $this->assertResponse(200);    
+  
+    // Add a different content with the comment field attached is needed to 
+    // reproduce the error.
+    // Generate a random subject/body.
+    $title = $this->randomName(20);
+    $body = $this->randomName(200);
+
+    $edit = array(
+      'title' => $title,
+      'body[0][value]' => $body,
+    );
+    $tid = 1;
+
+    // Create the forum topic, preselecting the forum ID via a URL parameter.
+    $this->drupalPostForm('node/add/forum', $edit, t('Save'), array('query' => array('forum_id' => $tid)));    
+
+    // Disable the forum module.
+    $edit = array();
+    $edit['uninstall[forum]'] = TRUE;
+    $this->drupalPostForm('admin/modules/uninstall', $edit, t('Uninstall'));
+    $this->drupalPostForm(NULL, array(), t('Uninstall'));
+    $this->rebuildContainer();
+    $this->assertFalse($this->container->get('module_handler')->moduleExists('forum'), 'Forum module uninstalled.');
+
+    $this->drupalGet('node/add/article'); 
+    
+    // Generate a random subject/body.
+    $title = $this->randomName(20);
+    $body = $this->randomName(200);
+
+    $edit = array(
+      'title' => $title,
+      'body[0][value]' => $body,
+    );
+
+    // Create an article.
+    $this->drupalPostForm('node/add/article', $edit, t('Save')); 
+    
+    // Go to the content page to verify that no error appears.
+    $this->drupalGet('admin/content');
+    $this->assertRaw('Content | ', 'Content page is loaded as expected.');
+
+  }
 }
diff --git a/core/modules/comment/lib/Drupal/comment/Tests/CommentTestBase.php b/core/modules/comment/lib/Drupal/comment/Tests/CommentTestBase.php
index 5a88dd6..2fdc60c 100644
--- a/core/modules/comment/lib/Drupal/comment/Tests/CommentTestBase.php
+++ b/core/modules/comment/lib/Drupal/comment/Tests/CommentTestBase.php
@@ -21,7 +21,7 @@
    *
    * @var array
    */
-  public static $modules = array('comment', 'node', 'history', 'field_ui', 'datetime');
+  public static $modules = array('comment', 'node', 'history', 'field_ui', 'datetime', 'number', 'options', 'taxonomy', 'forum');
 
   /**
    * An administrative user with permission to configure comment settings.
@@ -63,6 +63,8 @@ function setUp() {
       'post comments',
       'access comments',
       'access content',
+      'administer modules',
+      'administer users'
      ));
     $this->web_user = $this->drupalCreateUser(array(
       'access comments',