diff --git a/src/testdir/test_substitute.vim b/src/testdir/test_substitute.vim
index 8a8e7ab..e8b0e49 100644
--- a/src/testdir/test_substitute.vim
+++ b/src/testdir/test_substitute.vim
@@ -413,6 +413,7 @@
   for t in a:tests
     let start = line('.') + 1
     let end = start + len(t[2]) - 1
+    " TODO: why is there a one second delay the first time we get here?
     exe "normal o" . t[0]
     call cursor(start, 1)
     exe t[1]
@@ -716,3 +717,12 @@
 
   close!
 endfunc
+
+func Test_sub_beyond_end()
+  new
+  call setline(1, '#')
+  let @/ = '^#\n\zs'
+  s///e
+  call assert_equal('#', getline(1))
+  bwipe!
+endfunc