diff --git a/includes/ajax.inc b/includes/ajax.inc
index 41c6983..99477b4 100644
--- a/includes/ajax.inc
+++ b/includes/ajax.inc
@@ -651,7 +651,6 @@ function ajax_pre_render_element($element) {
 
   // Attach JavaScript settings to the element.
   if (isset($element['#ajax']['event'])) {
-    $element['#attached']['library'][] = array('system', 'jquery.form');
     $element['#attached']['library'][] = array('system', 'drupal.ajax');
 
     $settings = $element['#ajax'];
diff --git a/modules/system/system.module b/modules/system/system.module
index 5af9ad4..e4a1d76 100644
--- a/modules/system/system.module
+++ b/modules/system/system.module
@@ -1087,7 +1087,7 @@ function system_library() {
       'misc/ajax.js' => array('group' => JS_LIBRARY, 'weight' => 2),
     ),
     'dependencies' => array(
-      array('system', 'drupal.progress'),
+      array('system', 'jquery.form', 'drupal.progress'),
     ),
   );