dbms_metadata gives invalid DDL for db_links under 11.2.0.4

We use dbms_metadata.get_ddl to capture database links prior to refreshing a development database.

On databases that have been patched to 11.2.0.4, the procedure returns an invalid value for the password hash.

It literally returns ':1'

Here is an example of what it returns:

db_link_sql := dbms_metadata.get_ddl(object_type => 'DB_LINK', name => 'MYLINK.WORLD', schema=> 'MYSCHEMA');

Result:

CREATE DATABASE LINK "MYLINK.WORLD"

  CONNECT TO "MYUSER" IDENTIFIED BY VALUES '':1''

  USING ''DB''');

Has anyone seen this before?  Is it a bug, or do I need to do something different in 11.2.0.4?

Thanks

-Greg