No PUBLIC access by default?

Hi all-

Is there any way to disable PUBLIC access by default? When I create a
new object (table, function, etc.), it has no ACL, as expected.
However, the first time I run:

GRANT ALL ON FUNCTION foo() to GROUP developers;

Postgress seems to do:

GRANT ALL ON FUNCTION foo() to PUBLIC;

I assume this is b/c no ACL is equivalent to PUBLIC access & this gets
included when adding specific privileges.

I want *no* PUBLIC access to anything by default for security reasons.
Is there a way to prevent this behavior?