short sql question

Hi,

I just cannot see what is wrong with my query:

create table files (id int, name text, prev_name text, ....);
create table fnchanged (id int, name text);

update files f set prev_name = f.name, name = c.name from fnchanges c where f.id = c.id and c.name != f.name

--- gets syntax error at "from"

(Using PostgreSQL 10.4 on a NAS box)

Best regards
Wolfgang