Installing statspack on oracle 8.1.6

[rk0000]

We have oracle 8.1.6 installed on IBM AIX 4.3.
I am installing Statspack on oracle. I connect as "sys" and execute the script from rdbms/admin/statscre.sql
I got the following error at the end. how to solve this?

Creating Package Body STATSPACK...

Warning: Package Body created with compilation errors.

Errors for PACKAGE BODY STATSPACK:

LINE/COL ERROR
-------- -----------------------------------------------------------------
752/7 PL/SQL: SQL Statement ignored
752/14 PLS-00320: the declaration of the type of this expression is
incomplete or malformed

753/14 PLS-00201: identifier 'SYS.V$SESSION' must be declared
789/10 PL/SQL: SQL Statement ignored
1061/6 PL/SQL: SQL Statement ignored
1077/13 PLS-00201: identifier 'SYS.V$SESSION' must be declared

NOTE:
STATSPACK complete. Please check statspack.lis for any errors.

not spooling currently
SQL> desc SYS.V$SESSION
ERROR:
ORA-04043: object SYS.V$SESSION does not exist

thanks