diff --git a/src/testdir/test_fold.vim b/src/testdir/test_fold.vim
index 3bdd99f..2618084 100644
--- a/src/testdir/test_fold.vim
+++ b/src/testdir/test_fold.vim
@@ -1476,6 +1476,8 @@
   call assert_equal([0, 1, 1, 2, 2], range(1, 5)->map('foldlevel(v:val)'))
   call append(2, 'line 2.5')
   call assert_equal([0, 1, 0, 1, 2, 2], range(1, 6)->map('foldlevel(v:val)'))
+  3d
+  call assert_equal([0, 1, 1, 2, 2], range(1, 5)->map('foldlevel(v:val)'))
   bw!
 endfunc