diff --git a/core/modules/comment/lib/Drupal/comment/Tests/CommentFieldsTest.php b/core/modules/comment/lib/Drupal/comment/Tests/CommentFieldsTest.php
index 6e33e36..c0f806f 100644
--- a/core/modules/comment/lib/Drupal/comment/Tests/CommentFieldsTest.php
+++ b/core/modules/comment/lib/Drupal/comment/Tests/CommentFieldsTest.php
@@ -146,6 +146,7 @@ function testCommentFieldUI() {
 
     // Delete the field through the UI.
     $this->drupalPost('admin/structure/types/manage/test_node_type/comment/fields/field_test_field/delete', array(), t('Delete'));
+    $this->assertResponse(200);
 
     // Confirm that the field is no longer present
     $this->drupalGet('comment/reply/' . $node->nid);
diff --git a/core/modules/field_ui/lib/Drupal/field_ui/Tests/FieldUiTestBase.php b/core/modules/field_ui/lib/Drupal/field_ui/Tests/FieldUiTestBase.php
index 39324bf..9df56b7 100644
--- a/core/modules/field_ui/lib/Drupal/field_ui/Tests/FieldUiTestBase.php
+++ b/core/modules/field_ui/lib/Drupal/field_ui/Tests/FieldUiTestBase.php
@@ -124,6 +124,7 @@ function fieldUIDeleteField($bundle_path, $field_name, $label, $bundle_label) {
 
     // Submit confirmation form.
     $this->drupalPost(NULL, array(), t('Delete'));
+    $this->assertResponse(200);
     $this->assertRaw(t('The field %label has been deleted from the %type content type.', array('%label' => $label, '%type' => $bundle_label)), 'Delete message was found.');
 
     // Check that the field does not appear in the overview form.