diff --git a/common.yaml.jinja b/common.yaml.jinja
index 76bdc577..f5a94009 100644
--- a/common.yaml.jinja
+++ b/common.yaml.jinja
@@ -39,6 +39,7 @@ services:
     environment:
       POSTGRES_DB: *dbname
       POSTGRES_USER: *dbuser
+      PGHOST: "${DB_HOST:-db}"
       CONF_EXTRA: |
         work_mem = 512MB
     volumes:
diff --git a/prod.yaml.jinja b/prod.yaml.jinja
index b95f78e0..5a396e95 100644
--- a/prod.yaml.jinja
+++ b/prod.yaml.jinja
@@ -87,6 +87,8 @@ services:
     extends:
       file: common.yaml
       service: db
+    environment:
+      - DB_HOST={{ _key }}-db
     env_file:
       - .docker/db-creation.env
     restart: unless-stopped
diff --git a/test.yaml.jinja b/test.yaml.jinja
index 7d6106ee..cd0d1f26 100644
--- a/test.yaml.jinja
+++ b/test.yaml.jinja
@@ -63,6 +63,8 @@ services:
       service: db
     env_file:
       - .docker/db-creation.env
+    environment:
+      - DB_HOST={{ _key }}-db
     restart: unless-stopped
   {%- endif %}