How to join tables with conflicting collations?

I don't know how to compare objects from tables with different collations.  See below.

select tablename from itd_csdw.tablemaint where tablename in (select table_Name from dba_tables);

                                                                     *

ERROR at line 1:

ORA-43915: unable to determine collation: arguments have conflicting collations

Here's the DDL for the table.

select dbms_metadata.get_ddl('TABLE','TABLEMAINT','ITD_CSDW') from dual

/

DBMS_METADATA.GET_DDL('TABLE','TABLEMAINT','ITD_CSDW')

--------------------------------------------------------------------------------

CREATE TABLE "ITD_CSDW"."TABLEMAINT"

   (   "TABLENAME" VARCHAR2(50) COLLATE BINARY_CI NOT NULL ENABLE,

   ) ...

DEFAULT COLLATION BINARY_CI...

COLUMN STORE COMPRESS FOR QUERY HIGH..