diff --git a/core/modules/filter/lib/Drupal/filter/FilterFormatFormControllerBase.php b/core/modules/filter/lib/Drupal/filter/FilterFormatFormControllerBase.php
index 2146a59..4b49743 100644
--- a/core/modules/filter/lib/Drupal/filter/FilterFormatFormControllerBase.php
+++ b/core/modules/filter/lib/Drupal/filter/FilterFormatFormControllerBase.php
@@ -120,6 +120,7 @@ public function form(array $form, array &$form_state) {
       // If a filter is missing, it will have been replaced by the null filter.
       // Remove it here, so that saving the form will remove the missing filter.
       if ($filter instanceof FilterNull) {
+        drupal_set_message(t('The %filter filter is missing, and will be removed once this format is saved.', array('%filter' => $filter_id)), 'warning');
         $filters->removeInstanceID($filter_id);
       }
     }
diff --git a/core/modules/system/lib/Drupal/system/Tests/Upgrade/FilterFormatUpgradePathTest.php b/core/modules/system/lib/Drupal/system/Tests/Upgrade/FilterFormatUpgradePathTest.php
index bf2e13c..12561d7 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Upgrade/FilterFormatUpgradePathTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Upgrade/FilterFormatUpgradePathTest.php
@@ -80,12 +80,14 @@ public function testFilterFormatUpgrade() {
 
     // Try to use a filter format with a missing filter, this should not throw
     // an exception.
-    check_markup($this->randomName(), 'format_two');
+    $empty_markup = check_markup($this->randomName(), 'format_two');
+    $this->assertIdentical($empty_markup, '', 'The filtered text is empty while a filter is missing.');
 
     // Editing and saving the format should drop the missing filter.
-    $this->drupalGet('admin/config/content/formats/format_two');
+    $this->drupalGet('admin/config/content/formats/manage/format_two');
+    $this->assertRaw(t('The %filter filter is missing, and will be removed once this format is saved.', array('%filter' => 'missing_filter')));
     $this->drupalPost(NULL, array(), t('Save configuration'));
-    drupal_static_reset('filter_formats');
+    filter_formats_reset();
     $two = filter_format_load('format_two');
     $this->assertFalse($two->filters()->has('missing_filter'));