diff -u b/core/modules/forum/src/Tests/ForumUninstallTest.php b/core/modules/forum/src/Tests/ForumUninstallTest.php
--- b/core/modules/forum/src/Tests/ForumUninstallTest.php
+++ b/core/modules/forum/src/Tests/ForumUninstallTest.php
@@ -140,7 +140,7 @@
     $field_storage = FieldStorageConfig::loadByName('node', 'taxonomy_forums');
     $this->assertNull($field_storage, 'The taxonomy_forums field storage has been deleted.');
 
-    // Delete all terms in the Forums vocabulary. Uninstalling the form module
+    // Delete all terms in the Forums vocabulary. Uninstalling the forum module
     // will fail unless this is done.
     $terms = entity_load_multiple_by_properties('taxonomy_term', array('vid' => 'forums'));
     foreach($terms as $term) {
only in patch2:
unchanged:
--- a/core/modules/comment/src/Tests/CommentUninstallTest.php
+++ b/core/modules/comment/src/Tests/CommentUninstallTest.php
@@ -8,6 +8,7 @@
 namespace Drupal\comment\Tests;
 
 use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\Core\Extension\ModuleUninstallValidatorException;
 use Drupal\simpletest\WebTestBase;
 
 /**
@@ -36,19 +37,22 @@ protected function setUp() {
   }
 
   /**
-   * Tests if comment module uninstallation properly deletes the field.
+   * Tests if comment module uninstallation fails if the field exists.
+   *
+   * @throws \Drupal\Core\Extension\ModuleUninstallValidatorException
    */
   function testCommentUninstallWithField() {
     // Ensure that the field exists before uninstallation.
     $field_storage = FieldStorageConfig::loadByName('comment', 'comment_body');
     $this->assertNotNull($field_storage, 'The comment_body field exists.');
 
-    // Uninstall the comment module which should trigger field deletion.
-    $this->container->get('module_installer')->uninstall(array('comment'));
-
-    // Check that the field is now deleted.
-    $field_storage = FieldStorageConfig::loadByName('comment', 'comment_body');
-    $this->assertNull($field_storage, 'The comment_body field has been deleted.');
+    // Uninstall the comment module which should trigger an exception.
+    try {
+      $this->container->get('module_installer')->uninstall(array('comment'));
+      $this->fail("Expected an exception when uninstall was attempted.");
+    } catch (ModuleUninstallValidatorException $e) {
+      $this->pass("Caught an exception when uninstall was attempted.");
+    }
   }