[Dovecot] chroot lmtp, then can not open /usr/local/lib/dovecot

i want to chroot lmtp with sieve, but have some problem, look like lmtp can not load sieve's lib or something. the error message like this:

dovecot: lmtp(12799): Fatal: opendir(/usr/local/lib/dovecot) failed: No such file or directory

all is work fine, when not config lmtp chroot. can i config lmtp load sieve before chroot?

please help, and thank you.