diff --git a/magit.el b/magit.el
index a533c58e..40dfe6f8 100644
--- a/magit.el
+++ b/magit.el
@@ -1454,7 +1454,14 @@ Please see the manual for a complete description of Magit.
     nil))
 
 (defun magit-wash-untracked-files ()
-  (magit-wash-sequence #'magit-wash-untracked-file))
+  ;; Setting magit-old-top-section to nil speeds up washing: no time
+  ;; is wasted looking up the old visibility, which doesn't matter for
+  ;; untracked files.
+  ;;
+  ;; XXX - speed this up in a more general way.
+  ;;
+  (let ((magit-old-top-section nil))
+    (magit-wash-sequence #'magit-wash-untracked-file)))
 
 (defun magit-insert-untracked-files ()
   (magit-git-section 'untracked "Untracked files:"