diff --git a/directus/docker-compose.yml b/directus/docker-compose.yml
index f41d446..3b588c0 100644
--- a/directus/docker-compose.yml
+++ b/directus/docker-compose.yml
@@ -28,7 +28,7 @@ services:
       PUBLIC_URL: ${DIRECTUS_PUBLIC_URL:?err}
 
       DB_CLIENT: 'pg'
-      DB_HOST: ${POSTGRES_CONTAINER_NAME:-postgres}
+      DB_HOST: ${POSTGRES_CONTAINER_NAME:-postgres} # Default name is same as ../postgres/docker-compose.yml:8
       DB_PORT: '5432'
       DB_DATABASE: ${POSTGRES_DB:?err}
       DB_USER: ${POSTGRES_USER:?err}
diff --git a/gitea/docker-compose.yml b/gitea/docker-compose.yml
index 255d520..15415df 100644
--- a/gitea/docker-compose.yml
+++ b/gitea/docker-compose.yml
@@ -13,7 +13,7 @@ services:
       # - USER_UID=1000
       # - USER_GID=1000
       DB_TYPE: postgres
-      DB_HOST: postgres:5432
+      DB_HOST: ${POSTGRES_CONTAINER_NAME:-postgres}:5432 # Default name is same as ../postgres/docker-compose.yml:8
       DB_NAME: ${POSTGRES_DB}
       DB_USER: ${POSTGRES_USER}
       DB_PASSWD: ${POSTGRES_PASSWORD}
diff --git a/grafana/docker-compose.postgres.yml b/grafana/docker-compose.postgres.yml
index b9fc41c..2958291 100644
--- a/grafana/docker-compose.postgres.yml
+++ b/grafana/docker-compose.postgres.yml
@@ -5,7 +5,7 @@ services:
     environment:
       # https://grafana.com/docs/grafana/latest/administration/configuration/#database
       GF_DATABASE_TYPE: postgres
-      GF_DATABASE_HOST: postgres # Name is same as ../postgres/docker-compose.yml:8
+      GF_DATABASE_HOST: ${POSTGRES_CONTAINER_NAME:-postgres} # Default name is same as ../postgres/docker-compose.yml:8
       GF_DATABASE_NAME: ${POSTGRES_DB:?err}
       GF_DATABASE_USER: ${POSTGRES_USER:?err}
       GF_DATABASE_PASSWORD: ${POSTGRES_PASSWORD:?err}
diff --git a/hedgedoc/docker-compose.yml b/hedgedoc/docker-compose.yml
index 8b47dc8..0928bce 100644
--- a/hedgedoc/docker-compose.yml
+++ b/hedgedoc/docker-compose.yml
@@ -17,7 +17,7 @@ services:
       - /etc/localtime:/etc/localtime:ro
     environment:
       # https://docs.hedgedoc.org/configuration/
-      CMD_DB_URL: postgres://${POSTGRES_USER:?err}:${POSTGRES_PASSWORD:?err}@${POSTGRES_CONTAINER_NAME}:${POSTGRES_PORT:-5432}/${POSTGRES_DB:?err}
+      CMD_DB_URL: postgres://${POSTGRES_USER:?err}:${POSTGRES_PASSWORD:?err}@${POSTGRES_CONTAINER_NAME:-postgres}:${POSTGRES_PORT:-5432}/${POSTGRES_DB:?err}
       CMD_DOMAIN: ${HEDGEDOC_DOMAIN:?err}
       CMD_SESSION_SECRET: ${CMD_SESSION_SECRET:?err}
       NODE_ENV: ${NODE_ENV:-development} # `production` or `development`
diff --git a/mobilizon/docker-compose.yml b/mobilizon/docker-compose.yml
index e7f5c41..7a29ec5 100644
--- a/mobilizon/docker-compose.yml
+++ b/mobilizon/docker-compose.yml
@@ -31,7 +31,7 @@ services:
       MOBILIZON_DATABASE_USERNAME: ${POSTGRES_USER}
       MOBILIZON_DATABASE_PASSWORD: ${POSTGRES_PASSWORD}
       MOBILIZON_DATABASE_DBNAME: ${POSTGRES_DB}
-      MOBILIZON_DATABASE_HOST: ${POSTGRES_CONTAINER_NAME:-postgres}
+      MOBILIZON_DATABASE_HOST: ${POSTGRES_CONTAINER_NAME:-postgres} # Default name is same as ../postgres/docker-compose.yml:8
 
       MOBILIZON_INSTANCE_SECRET_KEY_BASE: ${MOBILIZON_INSTANCE_SECRET_KEY_BASE:?err}
       MOBILIZON_INSTANCE_SECRET_KEY: ${MOBILIZON_INSTANCE_SECRET_KEY:?err}