diff --git a/core/modules/system/system.install b/core/modules/system/system.install
index 2f0bd68..5e1443d 100644
--- a/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -1170,12 +1170,13 @@ function system_schema() {
  * Place local actions and tasks blocks in every theme.
  */
 function system_update_8001() {
-  // Nothing to do if block module is not installed.
+  // When block module is not installed, there is nothing that could be done
+  // except showing a warning.
   if (!\Drupal::moduleHandler()->moduleExists('block')) {
     return t('Block module is not enabled so local actions and tasks which have been converted to blocks, are not visible anymore.');
   }
   $config_factory = \Drupal::configFactory();
-  /** @var \Drupal\Core\Extension\ThemeHandler $theme_handler */
+  /** @var \Drupal\Core\Extension\ThemeHandlerInterface $theme_handler */
   $theme_handler = \Drupal::service('theme_handler');
   /** @var \Drupal\Core\Config\StorageInterface $config_storage */
   $config_storage = \Drupal::service('config.storage');
@@ -1204,7 +1205,6 @@ function system_update_8001() {
       'max_age' => 0,
     ],
   ];
-  /** @var \Drupal\Core\Extension\Extension $theme */
   foreach ($theme_handler->listInfo() as $theme) {
     $theme_name = $theme->getName();
     $block_storage = \Drupal::entityManager()->getStorage('block');
@@ -1229,15 +1229,25 @@ function system_update_8001() {
 
         // Help region has been removed so all the blocks inside has to be moved
         // to content region.
-        /* @var \Drupal\block\BlockInterface[] $help_blocks */
-        $help_blocks = $block_storage->loadByProperties(['theme' => 'bartik', 'region' => 'help']);
-        uasort($help_blocks, array('Drupal\Component\Utility\SortArray', 'sortByWeightProperty'));
         $weight = -6;
-        foreach ($help_blocks as $block) {
-          $block_config = $config_factory->getEditable('block.block.' . $block->getConfigTarget());
-          $block_config->set('region', 'content');
-          $block_config->set('weight', $weight);
-          $block_config->save();
+        $blocks = [];
+        foreach ($config_factory->listAll('block.block.') as $block_config) {
+          $block = $config_factory->getEditable($block_config);
+          if ($block->get('theme') == 'bartik' && $block->get('region') == 'help') {
+            $blocks[] = $block;
+          }
+        }
+        // Sort blocks by block weight.
+        uasort($blocks, function ($a, $b) {
+          $weight = $a->get('weight') - $b->get('weight');
+          return $weight;
+        });
+        // Move blocks to content region and set them in right order by their
+        // weight.
+        foreach ($blocks as $block) {
+          $block->set('region', 'content');
+          $block->set('weight', $weight);
+          $block->save();
           $weight++;
         }
         break;