WASHINGTON - Who says there’s no such thing as a free lunch? Z Burger in Northwest D.C. is giving away free hamburgers all day Thursday.

The only catches are:

1) There is a one burger limit per customer;
2) You have to know the secret codeword when ordering

That secret code word is “Yowza.”

There are two Z Burger locations in the District — but only the Tenleytown location on 4321 Wisconsin Ave. is offering the free food.

The chain is planning eight more locations in the Washington area.