diff --git a/templates/docker-compose.yml.j2 b/templates/docker-compose.yml.j2
index f04bff0..a8fc78b 100644
--- a/templates/docker-compose.yml.j2
+++ b/templates/docker-compose.yml.j2
@@ -2,6 +2,7 @@ services:
   db:
     # Note: Check the recommend version here: https://docs.nextcloud.com/server/latest/admin_manual/installation/system_requirements.html#server
     image: postgres:alpine
+    hostname: db
     restart: always
     volumes:
       - db:/var/lib/postgresql/data:Z
@@ -25,7 +26,7 @@ services:
       - POSTGRES_DATABASE=nextcloud
       - POSTGRES_HOST=db:5432
       - REDIS_HOST=redis
-      - NEXTCLOUD_TRUSTED_DOMAINS={{ inventory_hostname | default('ansible_undefined_host') }}
+      - NEXTCLOUD_TRUSTED_DOMAINS={{ inventory_hostname | default('ansible_undefined_variable')}}
     env_file:
       - .db.env
     networks:
@@ -39,6 +40,7 @@ services:
 
   web:
     image: nginx:alpine-slim
+    hostname: web
     restart: always
     volumes:
       # https://docs.nextcloud.com/server/latest/admin_manual/installation/nginx.html
@@ -46,8 +48,8 @@ services:
       # NOTE: The `volumes` included below should match those of the `app` container (unless you know what you're doing)
       - /home/{{ user.name }}/webroot:/var/www/html:z,ro
     environment:
-      - VIRTUAL_HOST={{ inventory_hostname | default('ansible_undefined_host') }}
-      - LETSENCRYPT_HOST={{ inventory_hostname | default('ansible_undefined_host') }}
+      - VIRTUAL_HOST={{ inventory_hostname | default('ansible_undefined_variable')}}
+      - LETSENCRYPT_HOST={{ inventory_hostname | default('ansible_undefined_variable')}}
       - LETSENCRYPT_EMAIL="admin@libre.audio"
     depends_on:
       - app
@@ -57,6 +59,7 @@ services:
 
   cron:
     image: nextcloud:fpm-alpine
+    hostname: cron
     restart: always
     volumes:
       - /home/{{ user.name }}/webroot:/var/www/html:z
@@ -69,6 +72,7 @@ services:
   # Warning: Do not use :latest tags of nginx-proxy unless absolutely sure about the consequences.
   proxy:
     image: nginxproxy/nginx-proxy:1.7-alpine
+    hostname: proxy
     restart: always
     ports:
       - 8080:80