diff --git a/core/includes/common.inc b/core/includes/common.inc
index 718a34b..01117ff 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -7925,12 +7925,10 @@ function queue($name, $reliable = FALSE) {
     if (!$class) {
       $class = variable_get('queue_default_class', 'Drupal\Core\Queue\System');
     }
-    $object = new $class($name);
-    if ($reliable && !$object instanceof ReliableQueueInterface) {
+    if ($reliable && in_array('ReliableQueueInterface', class_implements($class))) {
       $class = variable_get('queue_default_reliable_class', 'Drupal\Core\Queue\System');
-      $object = new $class($name);
     }
-    $queues[$name] = $object;
+    $queues[$name] = new $class($name);
   }
   return $queues[$name];
 }
diff --git a/core/modules/simpletest/tests/queue.test b/core/modules/simpletest/tests/queue.test
index ef34558..8ed251c 100644
--- a/core/modules/simpletest/tests/queue.test
+++ b/core/modules/simpletest/tests/queue.test
@@ -1,5 +1,8 @@
 <?php
 
+use Drupal\Core\Queue\Memory;
+use Drupal\Core\Queue\System;
+
 /**
  * Tests the basic queue functionality.
  */
@@ -13,15 +16,40 @@ class QueueTestCase extends DrupalWebTestCase {
   }
 
   /**
-   * Queues and dequeues a set of items to check the basic queue functionality.
+   * Tests the System queue.
    */
-  function testQueue() {
+  function testSystemQueue() {
     // Create two queues.
-    $queue1 = queue($this->randomName());
+    $queue1 = new System($this->randomName());
     $queue1->createQueue();
-    $queue2 = queue($this->randomName());
+    $queue2 = new System($this->randomName());
     $queue2->createQueue();
 
+    $this->queueTest($queue1, $queue2);
+  }
+
+  /**
+   * Tests the Memory queue.
+   */
+  function testMemoryQueue() {
+    // Create two queues.
+    $queue1 = new Memory($this->randomName());
+    $queue1->createQueue();
+    $queue2 = new Memory($this->randomName());
+    $queue2->createQueue();
+
+    $this->queueTest($queue1, $queue2);
+  }
+
+  /**
+   * Queues and dequeues a set of items to check the basic queue functionality.
+   *
+   * @param Drupal\Core\Queue\QueueInterface $queue1
+   *   An instantiated queue object.
+   * @param Drupal\Core\Queue\QueueInterface $queue2
+   *   An instantiated queue object.
+   */
+  function queueTest($queue1, $queue2) {
     // Create four items.
     $data = array();
     for ($i = 0; $i < 4; $i++) {