diff --git a/core/modules/block/block.module b/core/modules/block/block.module
index daea82cc973..ff137b1362c 100644
--- a/core/modules/block/block.module
+++ b/core/modules/block/block.module
@@ -575,6 +575,7 @@ function block_library_info() {
     'dependencies' => array(
       array('system', 'jquery'),
       array('system', 'drupal'),
+      array('system', 'drupal.ajax'),
     ),
   );