HSQLDB - How To Write Update SQL Statement With More Than One Table

I have a HSQLDB-database and the update syntax is as follows:

Java Code:

UPDATE table SET column = Expression [, ...] [WHERE Expression]; mh_sh_highlight_all('java');

Now I would like to update a column, with an inner join. Because inner join is not supported in this update-syntax I put the relationship in the where clause:

Java Code:

update table1 set rang=null where table1.column1 = table2.column1; mh_sh_highlight_all('java');

But HSQLDB is always saying to me that there is an syntax error: user lacks privilege or object not found: table2.column1

But I am 100% sure, that there is a table2 with the column1. I have no mistake in writing!