How do I force ag (the silver searcher) to list empty files

How do I get ag to list all files, including empty ones? +ravi@boxy:~$ mkdir new && cd new +ravi@boxy:~/new$ echo stuff > non-empty && touch empty +ravi@boxy:~/new$ ag -ul non-empty +ravi@boxy:~/new$ How do I get empty to appear in the example above?