[Dovecot] sievec error: "fileinto require missing"

I'm getting this error when compiling .dovecot.sieve:

    $ /usr/libexec/dovecot/sievec .dovecot.sieve .dovecot.sievec
    Info: line 3: fileinto require missing
    
    Unable to parse script: script errors:
    line 3: fileinto require missing

.dovecot.sieve just looks like this:

    $ cat .dovecot.sieve
    if header :contains ["List-Id"] ["dovecot.dovecot.org"]
    {
        fileinto "INBOX.dovecot";
        stop;
    }

I'm probably doing something silly; but I don't see how what I've done differs significantly from examples I've found. And googling for "fileinto require missing" just got me to the sievec source code.

What might be the problem here?

-- Braden McDaniel braden@endoframe.com