diff -u b/core/modules/aggregator/aggregator.install b/core/modules/aggregator/aggregator.install
--- b/core/modules/aggregator/aggregator.install
+++ b/core/modules/aggregator/aggregator.install
@@ -9,9 +9,9 @@
  * Implements hook_uninstall().
  */
 function aggregator_uninstall() {
-  $config = config('aggregator.admin');
-  $config->delete();
-  $config->save();
+  config('aggregator.admin')
+    ->delete()
+    ->save();
 }
 
 /**
@@ -268,7 +268,7 @@
 }
 
 /**
- * Moves aggregator settings from variable to config.
+ * Moves aggregator settings from variables to config.
  */
 function aggregrator_update_8000() {
   update_variables_to_config('aggregator.admin');
diff -u b/core/modules/aggregator/aggregator.module b/core/modules/aggregator/aggregator.module
--- b/core/modules/aggregator/aggregator.module
+++ b/core/modules/aggregator/aggregator.module
@@ -740,8 +740,7 @@
  *   The filtered content.
  */
 function aggregator_filter_xss($value) {
-  $config = config('aggregator.admin');
-  return filter_xss($value, preg_split('/\s+|<|>/', $config->get('aggregator_allowed_html_tags'), -1, PREG_SPLIT_NO_EMPTY));
+  return filter_xss($value, preg_split('/\s+|<|>/', config('aggregator.admin')->get('aggregator_allowed_html_tags'), -1, PREG_SPLIT_NO_EMPTY));
 }
 
 /**
diff -u b/core/modules/aggregator/aggregator.pages.inc b/core/modules/aggregator/aggregator.pages.inc
--- b/core/modules/aggregator/aggregator.pages.inc
+++ b/core/modules/aggregator/aggregator.pages.inc
@@ -218,10 +218,8 @@
       }
     }
     $done = TRUE;
-
-    $config = config('aggregator.admin');
     $form['categories'][$item->iid] = array(
-      '#type' => $config->get('aggregator_category_selector'),
+      '#type' => config('aggregator.admin')->get('aggregator_category_selector'),
       '#default_value' => $selected,
       '#options' => $categories,
       '#size' => 10,
@@ -358,9 +356,9 @@
   foreach ($result as $feed) {
     // Most recent items:
     $summary_items = array();
-    $config = config('aggregator.admin');
-    if ($config->get('aggregator_summary_items')) {
-      $items = db_query_range('SELECT i.title, i.timestamp, i.link FROM {aggregator_item} i WHERE i.fid = :fid ORDER BY i.timestamp DESC', 0, $config->get('aggregator_summary_items'), array(':fid' => $feed->fid));
+    $aggregator_summary_items = config('aggregator.admin')->get('aggregator_summary_items');
+    if ($aggregator_summary_items) {
+      $items = db_query_range('SELECT i.title, i.timestamp, i.link FROM {aggregator_item} i WHERE i.fid = :fid ORDER BY i.timestamp DESC', 0, $aggregator_summary_items, array(':fid' => $feed->fid));
       foreach ($items as $item) {
         $summary_items[] = theme('aggregator_summary_item', array('item' => $item));
       }
@@ -383,10 +381,10 @@
 
   $output = '';
   foreach ($result as $category) {
-    $config = config('aggregator.admin');
-    if ($config->get('aggregator_summary_items')) {
+    $aggregator_summary_items = config('aggregator.admin')->get('aggregator_summary_items');
+    if ($aggregator_summary_items) {
       $summary_items = array();
-      $items = db_query_range('SELECT i.title, i.timestamp, i.link, f.title as feed_title, f.link as feed_link FROM {aggregator_category_item} ci LEFT JOIN {aggregator_item} i ON i.iid = ci.iid LEFT JOIN {aggregator_feed} f ON i.fid = f.fid WHERE ci.cid = :cid ORDER BY i.timestamp DESC', 0, $config->get('aggregator_summary_items'), array(':cid' => $category->cid));
+      $items = db_query_range('SELECT i.title, i.timestamp, i.link, f.title as feed_title, f.link as feed_link FROM {aggregator_category_item} ci LEFT JOIN {aggregator_item} i ON i.iid = ci.iid LEFT JOIN {aggregator_feed} f ON i.fid = f.fid WHERE ci.cid = :cid ORDER BY i.timestamp DESC', 0, $aggregator_summary_items, array(':cid' => $category->cid));
       foreach ($items as $item) {
         $summary_items[] = theme('aggregator_summary_item', array('item' => $item));
       }
@@ -443,8 +441,7 @@
   foreach ($feeds as $feed) {
     switch ($feed_length) {
       case 'teaser':
-        $config = config('aggregator.admin');
-        $summary = text_summary($feed->description, NULL, $config->get('aggregator_teaser_length'));
+        $summary = text_summary($feed->description, NULL, config('aggregator.admin')->get('aggregator_teaser_length'));
         if ($summary != $feed->description) {
           $summary .= '<p><a href="' . check_url($feed->link) . '">' . t('read more') . "</a></p>\n";
         }
diff -u b/core/modules/aggregator/aggregator.processor.inc b/core/modules/aggregator/aggregator.processor.inc
--- b/core/modules/aggregator/aggregator.processor.inc
+++ b/core/modules/aggregator/aggregator.processor.inc
@@ -186,8 +186,7 @@
  *   Object describing feed.
  */
 function aggregator_expire($feed) {
-  $config = config('aggregator.admin');
-  $aggregator_clear = $config->get('aggregator_clear');
+  $aggregator_clear = config('aggregator.admin')->get('aggregator_clear');
 
   if ($aggregator_clear != AGGREGATOR_CLEAR_NEVER) {
     // Remove all items that are older than flush item timer.
diff -u b/core/modules/aggregator/aggregator.test b/core/modules/aggregator/aggregator.test
--- b/core/modules/aggregator/aggregator.test
+++ b/core/modules/aggregator/aggregator.test
@@ -944,8 +944,9 @@
     // Do not remove old aggregator items during these tests, since our sample
     // feeds have hardcoded dates in them (which may be expired when this test
     // is run).
-    $config = config('aggregator.admin');
-    $config->set('aggregator_clear', AGGREGATOR_CLEAR_NEVER);
+    config('aggregator.admin')
+      ->set('aggregator_clear', AGGREGATOR_CLEAR_NEVER)
+      ->save();
   }
 
   /**