diff --git a/docker-compose.yml b/docker-compose.yml
index 23d8c93..922339e 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -15,8 +15,8 @@ services:
     build:
       context: ./backend
       dockerfile: Dockerfile.dev
-    ports:
-      - "3000:3000"
+    # No host port mapping — dev traffic goes through the Docker nginx container.
+    # Production overlay maps 127.0.0.1:3000 for the host reverse proxy.
     environment:
       - DATABASE_URL=${DATABASE_URL}
       - REDIS_URL=${REDIS_URL}
@@ -43,8 +43,8 @@ services:
     build:
       context: ./frontend
       dockerfile: Dockerfile.dev
-    ports:
-      - "5173:5173"
+    # No host port mapping — dev traffic goes through the Docker nginx container.
+    # Production overlay maps 127.0.0.1:3001 for the host reverse proxy.
     environment:
       - NODE_ENV=${NODE_ENV}
     volumes: