diff --git a/Dockerfile b/Dockerfile
index 4678c2b..c1aa876 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -10,8 +10,8 @@ RUN install -dm 2750 -o root -g root /etc/ssl/private \
   && certtool --generate-dh-params --outfile=/etc/ssl/private/512.dh --bits=512 \
   && apk del gnutls-utils
 # Configure postfix
-RUN postconf -e alias_maps='hash:/etc/postfix/aliases' \
-  && postconf -e transport_maps='hash:/etc/postfix/transport' \
+RUN postconf -e alias_maps='lmdb:/etc/postfix/aliases' \
+  && postconf -e transport_maps='lmdb:/etc/postfix/transport' \
   && postconf -e recipient_delimiter='+' \
   && postconf -e sendmail_path='/usr/sbin/sendmail' \
   && postconf -e newaliases_path='/usr/bin/newaliases' \
@@ -66,7 +66,7 @@ RUN postconf -e alias_maps='hash:/etc/postfix/aliases' \
   && postconf -e non_smtpd_milters=inet:opendkim:8891 \
   && postconf -e milter_default_action=accept \
   && postconf -e milter_protocol=6 \
-  && postconf -e virtual_alias_maps=hash:/etc/postfix/maps/virtual \
+  && postconf -e virtual_alias_maps=lmdb:/etc/postfix/maps/virtual \
   && postconf -e sender_canonical_maps=tcp:postsrsd:10001 \
   && postconf -e sender_canonical_classes=envelope_sender \
   && postconf -e recipient_canonical_maps=tcp:postsrsd:10002 \