diff --git a/DOCKER.md b/DOCKER.md
index 2230f6c..4a833a0 100755
--- a/DOCKER.md
+++ b/DOCKER.md
@@ -56,7 +56,7 @@ mongosh "mongodb://admin:password123@localhost:27017/mozdit"
 ### 3. Alkalmazásból
 Az alkalmazás automatikusan csatlakozik:
 ```
-MONGODB_URI=mongodb://mongodb:27017/mozdit
+MONGODB_URI=mongodb://admin:password123@mongodb:27017/mozdit?authSource=admin
 ```
 
 ## 🛠️ Fejlesztési Parancsok
diff --git a/docker-compose.dev.yml b/docker-compose.dev.yml
index 86960a8..01a074b 100755
--- a/docker-compose.dev.yml
+++ b/docker-compose.dev.yml
@@ -12,7 +12,11 @@ services:
       - "127.0.0.1:8080:3000"
     environment:
       - NODE_ENV=development
-      - MONGODB_URI=mongodb://mongodb:27017/mozdit
+      # WHY authSource=admin: the mongodb service below only creates a root
+      # user (via MONGO_INITDB_ROOT_USERNAME/PASSWORD), which forces --auth
+      # on the mongod process — an unauthenticated URI fails every query
+      # with "Command find requires authentication" (MITHOME-98).
+      - MONGODB_URI=mongodb://admin:password123@mongodb:27017/mozdit?authSource=admin
       - MONGODB_DB=mozdit
       - NEXT_PUBLIC_SITE_URL=http://localhost:8080
       - NEXT_PUBLIC_COMPANY_NAME=mozdIT Bt.