changes to table creation syntax in 7.1.2?

In postgres 7.0.x I had some working code that lookes something like:

CREATE TABLE category
(   uid int4 PRIMARY KEY,   description text NOT NULL,   parent int4 NULL REFERENCES category(uid)
)

After upgrading to postgres 7.1.2 however this syntax is not accepted
anymore. I receive an error that says it can not create the reference
because the table category does not exist.

How do I setup this type of reference structure in 7.1.2? Did the syntax
change?

I am running under Linux.
--
Jayson Callaway