diff --git a/src/testdir/test_edit.vim b/src/testdir/test_edit.vim
index 6f083d9..0b44c7d 100644
--- a/src/testdir/test_edit.vim
+++ b/src/testdir/test_edit.vim
@@ -1704,6 +1704,7 @@
 endfunc
 
 " Test for editing a file without read permission
+" NOTE: if you run tests as root this will fail.  Don't run tests as root!
 func Test_edit_file_no_read_perm()
   CheckUnix
   call writefile(['one', 'two'], 'Xfile')