diff --git a/includes/bootstrap.inc b/includes/bootstrap.inc
index 1d590c2..9bf7a52 100644
--- a/includes/bootstrap.inc
+++ b/includes/bootstrap.inc
@@ -1100,7 +1100,6 @@ function drupal_file_scan_write_cache() {
   $file_scans = &_drupal_file_scan_cache();
   if (isset($file_scans['#write_cache'])) {
     unset($file_scans['#write_cache']);
-    unset($file_scans['#cache_merge_done']);
     cache_set('_drupal_file_scan_cache', $file_scans, 'cache_bootstrap');
   }
 }