Oracle Materialized Views with primary key

I created the Oracle Materialized View below:

CREATE MATERIALIZED VIEW MyMV
REFRESH COMPLETE ON DEMAND
AS

SELECT t1.*
  FROM table1 t1, table2 t2 where t1.id=t2.id;

The table1 has a primary key and the MV was created succesfully but the primary key was not created in the materialized view table.

Is there any other way to create MVs with primary keys?