diff --git a/includes/common.inc b/includes/common.inc
index ef000ecf59545e25472342df31f94f27dbec4443..c6fe6dd05a80fed6866eecb2da7795904d038348 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -1145,15 +1145,16 @@ function drupal_add_link($attributes) {
  * it adds "misc/drupal.js" to the output. Other scripts
  * depends on the 'killswitch' inside it.
  */
-function drupal_add_js($file) {
+function drupal_add_js($file, $nocache = FALSE) {
   static $sent = array();
 
+  $postfix = $nocache ? '?'. time() : '';
   if (!isset($sent['misc/drupal.js'])) {
-    drupal_set_html_head('<script type="text/javascript" src="'. base_path() .'misc/drupal.js"></script>');
+    drupal_set_html_head('<script type="text/javascript" src="'. base_path() .'misc/drupal.js'. $postfix .'"></script>');
     $sent['misc/drupal.js'] = true;
   }
   if (!isset($sent[$file])) {
-    drupal_set_html_head('<script type="text/javascript" src="'. check_url(base_path() . $file) .'"></script>');
+    drupal_set_html_head('<script type="text/javascript" src="'. check_url(base_path() . $file) . $postfix .'"></script>');
     $sent[$file] = true;
   }
 }
diff --git a/update.php b/update.php
index 917f016f1dd664dc4eb44b0356a8d81702e0ecc0..973ed1c8d7037baf05dab7618ea427d70ff5e185 100644
--- a/update.php
+++ b/update.php
@@ -353,8 +353,7 @@ function update_selection_page() {
 
   drupal_set_title('Drupal database update');
   // Prevent browser from using cached drupal.js or update.js
-  drupal_add_js('misc/update.js?'.time());
-  drupal_add_js('misc/drupal.js?'.time());
+  drupal_add_js('misc/update.js', TRUE);
   $output .= drupal_get_form('update_script_selection_form', $form);
 
   return $output;