diff --git a/.env b/.env
index 3560132..08955cd 100644
--- a/.env
+++ b/.env
@@ -1,19 +1,19 @@
-ELASTICSEARCH_VERSION=8.12.2
-IMAGE_REPO=ghcr.io/zammad/zammad
-MEMCACHE_SERVERS=zammad-memcached:11211
-MEMCACHE_VERSION=1.6.25-alpine
-POSTGRES_DB=zammad_production
-POSTGRES_PASS=zammad
-POSTGRES_USER=zammad
-POSTGRES_HOST=zammad-postgresql
-POSTGRES_PORT=5432
-POSTGRES_VERSION=15.6-alpine
-POSTGRESQL_OPTIONS=?pool=50
-REDIS_URL=redis://zammad-redis:6379
-REDIS_VERSION=7.2.4-alpine
-RESTART=always
+# ELASTICSEARCH_VERSION=8.12.2
+# IMAGE_REPO=ghcr.io/zammad/zammad
+# MEMCACHE_SERVERS=zammad-memcached:11211
+# MEMCACHE_VERSION=1.6.25-alpine
+# POSTGRES_DB=zammad_production
+# POSTGRES_PASS=zammad
+# POSTGRES_USER=zammad
+# POSTGRES_HOST=zammad-postgresql
+# POSTGRES_PORT=5432
+# POSTGRES_VERSION=15.6-alpine
+# POSTGRESQL_OPTIONS=?pool=50
+# REDIS_URL=redis://zammad-redis:6379
+# REDIS_VERSION=7.2.4-alpine
+# RESTART=always
 # Use a fixed version. You are responsible to update this to newer patch level versions yourself.
-VERSION=6.3.1
+# VERSION=6.3.1
 # You can also use floating versions that will give you automatic updates:
 # VERSION=6.2     # all patchlevel updates
 # VERSION=6       # including minor updates
diff --git a/docker-compose.yml b/docker-compose.yml
index 5438794..2ea006d 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -4,13 +4,15 @@ version: '3.8'
 x-shared:
   zammad-service: &zammad-service
     environment: &zammad-environment
-      MEMCACHE_SERVERS: ${MEMCACHE_SERVERS}
-      POSTGRESQL_DB: ${POSTGRES_DB}
-      POSTGRESQL_HOST: ${POSTGRES_HOST}
-      POSTGRESQL_USER: ${POSTGRES_USER}
-      POSTGRESQL_PASS: ${POSTGRES_PASS}
-      POSTGRESQL_PORT: ${POSTGRES_PORT}
-      REDIS_URL: ${REDIS_URL}
+      MEMCACHE_SERVERS: ${MEMCACHE_SERVERS:-zammad-memcached:11211}
+      POSTGRESQL_DB: ${POSTGRES_DB:-zammad_production}
+      POSTGRESQL_HOST: ${POSTGRES_HOST:-zammad-postgresql}
+      POSTGRESQL_USER: ${POSTGRES_USER:-zammad}
+      POSTGRESQL_PASS: ${POSTGRES_PASS:-zammad}
+      POSTGRESQL_PORT: ${POSTGRES_PORT:-5432}
+      POSTGRESQL_OPTIONS: ${POSTGRESQL_OPTIONS:-?pool=50}
+      POSTGRESQL_DB_CREATE:
+      REDIS_URL: ${REDIS_URL:-redis://zammad-redis:6379}
       # Allow passing in these variables via .env:
       AUTOWIZARD_JSON:
       AUTOWIZARD_RELATIVE_PATH:
@@ -24,15 +26,13 @@ x-shared:
       NGINX_PORT:
       NGINX_SERVER_NAME:
       NGINX_SERVER_SCHEME:
-      POSTGRESQL_DB_CREATE:
-      POSTGRESQL_OPTIONS:
       RAILS_TRUSTED_PROXIES:
       ZAMMAD_WEB_CONCURRENCY:
       ZAMMAD_SESSION_JOBS:
       ZAMMAD_PROCESS_SCHEDULED:
       ZAMMAD_PROCESS_DELAYED_JOBS_WORKERS:
-    image: ${IMAGE_REPO}:${VERSION}
-    restart: ${RESTART}
+    image: ${IMAGE_REPO:-ghcr.io/zammad/zammad}:${VERSION:-6.3.1}
+    restart: ${RESTART:-always}
     volumes:
       - zammad-storage:/opt/zammad/storage
     depends_on:
@@ -53,16 +53,16 @@ services:
       BACKUP_TIME: "03:00"
       HOLD_DAYS: "10"
       TZ: Europe/Berlin
-    image: postgres:${POSTGRES_VERSION}
-    restart: ${RESTART}
+    image: postgres:${POSTGRES_VERSION:-15.6-alpine}
+    restart: ${RESTART:-always}
     volumes:
       - zammad-backup:/var/tmp/zammad
       - zammad-storage:/opt/zammad/storage:ro
       - ./scripts/backup.sh:/usr/local/bin/backup.sh:ro
 
   zammad-elasticsearch:
-    image: bitnami/elasticsearch:${ELASTICSEARCH_VERSION}
-    restart: ${RESTART}
+    image: bitnami/elasticsearch:${ELASTICSEARCH_VERSION:-8.12.2}
+    restart: ${RESTART:-always}
     volumes:
       - elasticsearch-data:/bitnami/elasticsearch/data
 
@@ -78,8 +78,8 @@ services:
 
   zammad-memcached:
     command: memcached -m 256M
-    image: memcached:${MEMCACHE_VERSION}
-    restart: ${RESTART}
+    image: memcached:${MEMCACHE_VERSION:-1.6.25-alpine}
+    restart: ${RESTART:-always}
 
   zammad-nginx:
     <<: *zammad-service
@@ -91,11 +91,11 @@ services:
 
   zammad-postgresql:
     environment:
-      POSTGRES_DB: ${POSTGRES_DB}
-      POSTGRES_USER: ${POSTGRES_USER}
-      POSTGRES_PASSWORD: ${POSTGRES_PASS}
-    image: postgres:${POSTGRES_VERSION}
-    restart: ${RESTART}
+      POSTGRES_DB: ${POSTGRES_DB:-zammad_production}
+      POSTGRES_USER: ${POSTGRES_USER:-zammad}
+      POSTGRES_PASSWORD: ${POSTGRES_PASS:-zammad}
+    image: postgres:${POSTGRES_VERSION:-15.6-alpine}
+    restart: ${RESTART:-always}
     volumes:
       - postgresql-data:/var/lib/postgresql/data
 
@@ -104,8 +104,8 @@ services:
     command: ["zammad-railsserver"]
 
   zammad-redis:
-    image: redis:${REDIS_VERSION}
-    restart: ${RESTART}
+    image: redis:${REDIS_VERSION:-7.2.4-alpine}
+    restart: ${RESTART:-always}
     volumes:
       - redis-data:/data