diff --git a/core/modules/aggregator/aggregator.theme.inc b/core/modules/aggregator/aggregator.theme.inc
index ab6c3dc..b7b6f73 100644
--- a/core/modules/aggregator/aggregator.theme.inc
+++ b/core/modules/aggregator/aggregator.theme.inc
@@ -7,6 +7,7 @@
 
 use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Core\Render\Element;
+use Drupal\Core\Template\Attribute;
 
 /**
  * Prepares variables for aggregator item templates.
@@ -27,6 +28,7 @@ function template_preprocess_aggregator_item(&$variables) {
 
   $variables['url'] = check_url($item->getLink());
   $variables['title'] = SafeMarkup::checkPlain($item->label());
+  $variables['title_attributes'] = isset($variables['title_attributes']) ? new Attribute($variables['title_attributes']) : new Attribute();
 }
 
 /**
@@ -47,4 +49,5 @@ function template_preprocess_aggregator_feed(&$variables) {
   }
   $variables['full'] = $variables['elements']['#view_mode'] == 'full';
   $variables['title'] = SafeMarkup::checkPlain($feed->label());
+  $variables['title_attributes'] = isset($variables['title_attributes']) ? new Attribute($variables['title_attributes']) : new Attribute();
 }