diff --git a/target/dovecot/10-mail.conf b/target/dovecot/10-mail.conf
index f91fd1b2..9fcd3c24 100644
--- a/target/dovecot/10-mail.conf
+++ b/target/dovecot/10-mail.conf
@@ -206,7 +206,9 @@ mail_privileged_group = docker
 
 # Space separated list of plugins to load for all services. Plugins specific to
 # IMAP, LDA, etc. are added to this list in their own .conf files.
-mail_plugins = $mail_plugins quota
+mail_plugins {
+  quota = yes
+}
 
 ##
 ## Mailbox handling optimizations
diff --git a/target/dovecot/20-imap.conf b/target/dovecot/20-imap.conf
index 161c2150..fbd50637 100644
--- a/target/dovecot/20-imap.conf
+++ b/target/dovecot/20-imap.conf
@@ -1,4 +1,6 @@
 protocol imap {
-    # allow IMAP clients to ask quota usage
-    mail_plugins = $mail_plugins imap_quota
+  # allow IMAP clients to ask quota usage
+  mail_plugins {
+    imap_quota = yes
+  }
 }
diff --git a/target/dovecot/20-lmtp.conf b/target/dovecot/20-lmtp.conf
index 29c08bd6..5634f07c 100644
--- a/target/dovecot/20-lmtp.conf
+++ b/target/dovecot/20-lmtp.conf
@@ -15,5 +15,7 @@
 
 protocol lmtp {
   # Space separated list of plugins to load (default is global mail_plugins).
-  mail_plugins = $mail_plugins sieve
+  mail_plugins {
+    sieve = yes
+  }
 }