operator @> does not work with box.

I do

select circle '((0,0),3)' @> point '(0,0)';

and I get true.

I do

select box '((0,0),(1,1))' @> point '(0,0)';

and I get this:

ERROR:  operator does not exist: box @> point
ROW 1: select box '((0,0),(1,1))' @> point '(0,0)';
                                  ^
HINT:  No operator matches the given name and argument type(s). You
might need to add explicit type casts.

I'm using 8.4.4 and I feel confused. What am I doing wrong here?