PostgreSQL external functions under OpenBSD

Hello.

I was trying to compile external function for PostgreSQL under OpenBSD 2.6 and
failed.

I did:

gcc -fpic -c -o test.o test.c
ld -Nshareable -o test.so test.o

Then I created postgres function from test.so module. But it doesn't work
showing:
ERROR: init_fcache: Cache lookup failed for procedure 139520

Could somebody point me where I did something wrong?

P.S. I used following code

DROP FUNCTION test();
CREATE FUNCTION test() RETURNS int4
AS '/usr/local/pgsql/lib/test.so' LANGUAGE 'c';

--
Alexey