You can't specify target table for update in FROM clause

[Douglass Davis]

How can I do the following in a single query:

UPDATE acx_project_users u_invited
SET user_id = 38
WHERE user_id = 5514
AND NOT EXISTS (
SELECT 1 FROM
acx_project_users u_existing
WHERE u_existing.user_id = u_invited.user_id
AND u_existing.project_id = u_invited.project_id
)

The above query gives me an error of

Error Code: 1093. You can't specify target table 'u_invited' for update in FROM clause

Basically all I want to do is change from one user id to another, but not if there is already a row with that user id and project id