User password update error

[Goedendag]

Upon trying to update a user password I get:

DB Error: [1305] FUNCTION roundcube.update_passwd does not exist (SQL Query: SELECT update_passwd(
etc.

I know I should configure the password plugin correctly, which I did:

$config['password_db_dsn'] = 'mysql://redacted:redacted@localhost/redacted';
$config['password_query'] = 'UPDATE redacted SET password=%P WHERE redacted=%u';

However, as one can see in the error above, it looks like it's completely disregarding this config...
Does anyone know what I am doing wrong? - Thanks in advance!

[SKaero]

Where have you set the config options?