SQL & PL/SQL

I have a SQL Script that does this:
conn pnr/<password for user pnr>;
set serveroutput on;
exec vms.disable_all_fk_constraints;
SELECT owner, constraint_name, status FROM user_constraints WHERE constraint_type = 'R';

and the disable_all_fk_constraints procedure that is owned by user 'vms' is defined as:
create or replace
procedure disable_all_fk_constraints is
v_sql VARCHAR2(4000);
begin
dbms_output.put_line('Disabling all referential integrity constraints.');
for rec in (SELECT table_name, constraint_name FROM user_constraints WHERE constraint_type='R') loop
dbms_output.put_line('Disabling constraint ' || rec.constraint_name || ' from ' || rec.table_name || '.');
v_sql := 'ALTER TABLE ' || rec.table_name || ' DISABLE CONSTRAINT ' || rec.constraint_name;
execute immediate(v_sql);
end loop;
end;

When I run the SQL script, the call to vms.disable_all_fk_constraints disables the FK constrains in the 'vms' schema, whereas I wanted it to disable the FK constraints in the 'pnr' schema (the invoker of the procedure). I know that I could make this work by copying the disable_all_fk_constraints procedure to the 'pnr' schema and calling it as "+exec disable_all_fk_constraints;+" from within the SQL script but I want to avoid having to duplicate the PL/SQL procedure in each schema that uses it.

What can I do?

Thank you