diff --git a/modules/system/system.queue.inc b/modules/system/system.queue.inc
index 3e2979be1e3b..be0c31e97ec8 100644
--- a/modules/system/system.queue.inc
+++ b/modules/system/system.queue.inc
@@ -158,15 +158,6 @@ interface DrupalQueueInterface {
  * Default queue implementation.
  */
 class SystemQueue implements DrupalQueueInterface {
-  /**
-   * Our internal consumer ID for this queue instance.
-   *
-   * This is created lazily when we start consuming items with claimItem().
-   *
-   * @var integer
-   */
-  protected $consumerId;
-
   /**
    * The name of the queue this instance is working with.
    *