diff --git a/docker-compose.yml b/docker-compose.yml
index 2f5b8ef..c8fc88f 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -7,7 +7,7 @@ services:
       - ml-data:/app/ml-data
     environment:
       - NODE_ENV=production
-      - DATABASE_URL=postgresql://ml_user:ml_password@postgres:5432/candle_annotator
+      - DATABASE_URL=postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@postgres:5432/${POSTGRES_DB}
       - INFERENCE_API_URL=http://ml-service:8001
       - INFERENCE_API_TIMEOUT=30000
       - INFERENCE_BATCH_TIMEOUT=120000
@@ -34,7 +34,7 @@ services:
       - mlflow-data:/app/mlruns
     environment:
       - MLFLOW_TRACKING_URI=http://mlflow:5000
-      - DATABASE_URL=postgresql://ml_user:ml_password@postgres:5432/candle_annotator
+      - DATABASE_URL=postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@postgres:5432/${POSTGRES_DB}
       - PYTHONUNBUFFERED=1
     restart: unless-stopped
     depends_on:
@@ -70,12 +70,12 @@ services:
     volumes:
       - postgres-data:/var/lib/postgresql/data
     environment:
-      - POSTGRES_USER=ml_user
-      - POSTGRES_PASSWORD=ml_password
-      - POSTGRES_DB=candle_annotator
+      - POSTGRES_USER=${POSTGRES_USER}
+      - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}
+      - POSTGRES_DB=${POSTGRES_DB}
     restart: unless-stopped
     healthcheck:
-      test: ["CMD-SHELL", "pg_isready -U ml_user -d candle_annotator"]
+      test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER} -d ${POSTGRES_DB}"]
       interval: 10s
       timeout: 5s
       retries: 5
diff --git a/openspec/changes/code-review-fix/tasks.md b/openspec/changes/code-review-fix/tasks.md
index 17f4dc5..1c42314 100644
--- a/openspec/changes/code-review-fix/tasks.md
+++ b/openspec/changes/code-review-fix/tasks.md
@@ -4,7 +4,7 @@
 - [x] 1.2 `[haiku]` Add `models/` and `*.pkl` to `.gitignore`
 - [x] 1.3 `[haiku]` Replace real credentials in `.env.example` with placeholders (`POSTGRES_PASSWORD=change_me_to_a_strong_password`)
 - [x] 1.4 `[haiku]` Remove SQL comment with credentials from `services/ml/app/db.py` and add fail-fast check for missing `DATABASE_URL`
-- [ ] 1.5 `[sonnet]` Update `docker-compose.yml` to use `${POSTGRES_USER}`, `${POSTGRES_PASSWORD}`, `${POSTGRES_DB}` env var interpolation in all DATABASE_URL values
+- [x] 1.5 `[sonnet]` Update `docker-compose.yml` to use `${POSTGRES_USER}`, `${POSTGRES_PASSWORD}`, `${POSTGRES_DB}` env var interpolation in all DATABASE_URL values
 - [ ] 1.6 `[haiku]` Bind PostgreSQL port to `127.0.0.1:5432:5432` in `docker-compose.yml`
 - [ ] 1.7 `[haiku]` Bind MLflow port to `127.0.0.1:5000:5000` in `docker-compose.yml`
 - [ ] 1.8 `[haiku]` Bind ML service port to `127.0.0.1:8001:8001` in `docker-compose.yml`