SQLSTATE 42X10 occurs when qualifying a column with a synonym in ORDER BY clause

SQLSTATE 42X10 occurs when qualifying a column with a synonym in ORDER BY clause, where the synonym was declared in a different schema:

ij version 10.3
ij> connect 'jdbc:derby:wombat;create=true';
ij> create schema test1;
0 rows inserted/updated/deleted
ij> create schema test2;
0 rows inserted/updated/deleted
ij> create table test1.testtable(id bigint not null);
0 rows inserted/updated/deleted
ij> create synonym test2.testtable for test1.testtable;
0 rows inserted/updated/deleted
ij> set schema test1;
0 rows inserted/updated/deleted
ij> select testtable.id from testtable;
ID
--------------------

0 rows selected
ij> set schema test2;
0 rows inserted/updated/deleted
ij> select testtable.id from testtable;
ID
--------------------

0 rows selected
ij> select testtable.id from testtable order by testtable.id;
ERROR 42X10: 'TESTTABLE' is not an exposed table name in the scope in which it appears.
ij>