diff --git a/core/includes/common.inc b/core/includes/common.inc
index 15e672e..c3804bd 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -4495,11 +4495,11 @@ function drupal_cron_run() {
 
   foreach ($queues as $queue_name => $info) {
     if (isset($info['cron'])) {
-      $function = $info['worker callback'];
+      $callback = $info['worker callback'];
       $end = time() + (isset($info['cron']['time']) ? $info['cron']['time'] : 15);
       $queue = Drupal::queue($queue_name);
       while (time() < $end && ($item = $queue->claimItem())) {
-        $function($item->data);
+        call_user_func_array($callback, array($item->data));
         $queue->deleteItem($item);
       }
     }
diff --git a/core/modules/system/system.api.php b/core/modules/system/system.api.php
index 32e4efc..e44ca99 100644
--- a/core/modules/system/system.api.php
+++ b/core/modules/system/system.api.php
@@ -211,7 +211,7 @@ function hook_data_type_info_alter(&$data_types) {
  * @return
  *   An associative array where the key is the queue name and the value is
  *   again an associative array. Possible keys are:
- *   - 'worker callback': The name of the function to call. It will be called
+ *   - 'worker callback': A PHP callable to call. It will be called
  *     with one argument, the item created via
  *     Drupal\Core\Queue\QueueInterface::createItem() in hook_cron().
  *   - 'cron': (optional) An associative array containing the optional key:
@@ -226,7 +226,7 @@ function hook_data_type_info_alter(&$data_types) {
 function hook_queue_info() {
   $queues['aggregator_feeds'] = array(
     'title' => t('Aggregator refresh'),
-    'worker callback' => 'aggregator_refresh',
+    'worker callback' => array('Drupal\my_module\MyClass', 'aggregatorRefresh'),
     // Only needed if this queue should be processed by cron.
     'cron' => array(
       'time' => 60,