How to make DictCursor the default cursor with psycopg2+twisted?

In my small python scripts, I usually use DictCursors like this:

curs = db.cursor(cursor_factory = psycopg2.extras.DictCursor)

Now I'd like to do the same thing using Twisted, but you only pass db
connection parameters and sql query paramaters through Twisted to
psycopg, while Twisted handles everything else (including cursors)
itself.

Is there a way to globally configure psycopg2 so that it used
psycopg2.extras.DictCursor by default?

~ Nathan