table inheritance and foreign key troubles

I'm having a little trouble with some inherited tables and a foreign key. Here's
a simplified case, to show the trouble.

CREATE TABLE node (
node_id SERIAL NOT NULL,
name TEXT NOT NULL,
PRIMARY KEY (node_id)
);
-- works just fine

CREATE TABLE users (
email TEXT NOT NULL
) INHERITS (node);
-- so far so good....

CREATE TABLE item (
reason TEXT NOT NULL,
author_id INT NOT NULL REFERENCES users (node_id)
) INHERITS (node);
ERROR: UNIQUE constraint matching given keys for referenced table "users" not found

Does this operation just require differing syntax, because the referenced field
is inherited from another table, or is this not possible?

Kevin Way