diff --git a/playbooks/roles/mail/templates/docker-compose.yml.j2 b/playbooks/roles/mail/templates/docker-compose.yml.j2
index 1f9e7ad..f71914c 100644
--- a/playbooks/roles/mail/templates/docker-compose.yml.j2
+++ b/playbooks/roles/mail/templates/docker-compose.yml.j2
@@ -18,6 +18,8 @@ services:
       - ROUNDCUBEMAIL_DEFAULT_PORT={{ roundcube_default_port }}
       - ROUNDCUBEMAIL_SMTP_SERVER={{ roundcube_smtp_host }}
       - ROUNDCUBEMAIL_SMTP_PORT={{ roundcube_smtp_port }}
+    networks:
+      - roundcube
 
   mailserver:
     image: ghcr.io/docker-mailserver/docker-mailserver:latest
@@ -69,3 +71,8 @@ services:
       - OAUTH2_INTROSPECTION_URL={{ roundcube_oauth2_user_uri }}
     extra_hosts:
       - {{ ldap_server }}:{{ ldap_intranet}}
+    networks:
+      - mailserver
+networks:
+  mailserver:
+  roundcube: