Trouble updating table with values from another table sqlite

For some reason other solutions on stackoverflow haven't gotten rid of the near ".": syntax error: I still see when I try to run the following command :

UPDATE topic SET topic.ArturoNumCompanies = (SELECT arturotopic.num_comps FROM arturotopic WHERE topicname = topic.TopicName);

also get the same error when i run :

UPDATE t1 SET t1.ArturoNumCompanies = t2.num_comps FROM topic t1, arturotopic t2 WHERE t1.TopicName = t2.topicName