diff --git a/.env.example b/.env.example
index 54e73fc..cc377a5 100644
--- a/.env.example
+++ b/.env.example
@@ -8,3 +8,4 @@ FLASK_ENV=production
 APP_CURRENCY=USD
 APP_CURRENCY_SYMBOL=$
 APP_TIMEZONE=Asia/Ho_Chi_Minh
+FLASK_APP=wsgi:app
diff --git a/deploy.md b/deploy.md
index b8868a1..34aaf5e 100644
--- a/deploy.md
+++ b/deploy.md
@@ -101,7 +101,7 @@ MAX_CONTENT_LENGTH=10485760
 FLASK_ENV=production
 APP_CURRENCY=USD
 APP_CURRENCY_SYMBOL=$
-APP_TIMEZONE=Asia/Ho_Chi_Minh
+APP_TIMEZONE=America/New_York
 ```
 
 ```bash
diff --git a/wsgi.py b/wsgi.py
index 3dc5f39..8c2d998 100644
--- a/wsgi.py
+++ b/wsgi.py
@@ -1,3 +1,9 @@
+import sys
+import os
+
+# Ensure the project root is on the path so 'app' package is always found
+sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
+
 from app import create_app
 
 app = create_app()