Dumping schemas using pg_dump without extensions (9.1 Beta)

I am trying to backup a single schema only, without any other database
objects such as extensions. pg_dump however always includes
extensions, even with the --schema=schema option specified (see below
for example). Is there a workaround for this?

Cheers,

Adrian

--
-- TOC entry 20 (class 3079 OID 11673)
-- Name: plpgsql; Type: EXTENSION; Schema: -; Owner: -
--

CREATE EXTENSION IF NOT EXISTS plpgsql WITH SCHEMA pg_catalog;

--
-- TOC entry 2978 (class 0 OID 0)
-- Dependencies: 20
-- Name: EXTENSION plpgsql; Type: COMMENT; Schema: -; Owner: -
--

COMMENT ON EXTENSION plpgsql IS 'PL/pgSQL procedural language';

--
-- TOC entry 19 (class 3079 OID 35645)
-- Name: adminpack; Type: EXTENSION; Schema: -; Owner: -
--

CREATE EXTENSION IF NOT EXISTS adminpack WITH SCHEMA pg_catalog;