ORA-01031 with materialized view in stored procedure

Question

USER1 has created a materialized view (MV). The MV is owned by USER2. USER1 needs to query the MV from within a stored procedure. How do I avoid the ORA-01031?
Here's the illustration:
SQL> show user
USER is "USER1"
SQL> CREATE MATERIALIZED VIEW USER2.ROLL
2 BUILD IMMEDIATE
3 REFRESH COMPLETE WITH ROWID
4 ON DEMAND
5 AS
6 select * from user2.test_roll;
Materialized view created.
SQL> select status,owner,object_name,object_type where OBJECT_TYPE='MATERIALIZED VIEW';
STATUS OWNER OBJECT_NAME OBJECT_TYPE
VALID USER2 ROLL MATERIALIZED VIEW
SQL> select count(*) from user2.roll;
COUNT(*)
959485
SQL> declare
2 n number;
3 begin
4 select count(*)
5 into n
6 from user2.roll
7 where rownum<100;
8 dbms_output.put_line(n);
9* end;
SQL> /
99
PL/SQL procedure successfully completed.
SQL> create procedure test_mv is
2 n number;
3 begin
4 select count(*)
5 into n
6 from as400_snpsht.roll
7 where rownum<100;
8 dbms_output.put_line(n);
9 end;
10 /
Warning: Procedure created with compilation errors.
SQL> select text from user_errors where name like 'TEST_MV';
TEXT
PL/SQL: ORA-01031: insufficient privileges
PL/SQL: SQL Statement ignored
So the point is:
* Ad hoc sql works on the MV
* Anonymous pl/sql works on the MV
* Stored procedure fails compilation with ora-01031
Any suggestions are appreciated.

Answer 1

Sorry; In may example 'as400_snpsht' should have been 'USER2' (the owner of the MV). I changed the real user names to USER1, USER2 to make the example clearer but missed that one.
I meant to say...
SQL> create procedure test_mv is
2 n number;
3 begin
4 select count(*)
5 into n
6 from user2.roll
7 where rownum<100;
8 dbms_output.put_line(n);
9 end;
10 /
Warning: Procedure created with compilation errors.
SQL> select text from user_errors where name like 'TEST_MV';
TEXT
PL/SQL: ORA-01031: insufficient privileges
PL/SQL: SQL Statement ignored