diff --git a/Dockerfile b/Dockerfile
index a802a15..53a1cca 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -12,6 +12,7 @@ COPY src/manage_users.py /app/src/
 RUN python /app/src/manage_users.py init
 ENV FLASK_APP=src/app.py
 ENV FLASK_RUN_HOST=0.0.0.0
+ENV FLASK_RUN_PORT=49152
 
 EXPOSE 49152
 
diff --git a/docker-compose.yml b/docker-compose.yml
index 3defe29..a2cd47f 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -10,6 +10,7 @@ services:
     environment:
       FLASK_APP: src/app.py
       FLASK_RUN_HOST: 0.0.0.0
+      FLASK_RUN_PORT: 49152
     command: sh -c "python /app/src/manage_users.py init && flask run"
 networks:
   shortn-network:
diff --git a/src/app.py b/src/app.py
index 9b243c3..f5c2429 100644
--- a/src/app.py
+++ b/src/app.py
@@ -139,6 +139,12 @@ def create_user():
             except sqlite3.IntegrityError:
                 return 'User already exists.'
 
+
+# 404
+@app.errorhandler(404)
+def page_not_found(e):
+    return render_template('404.html'), 404
+
 if __name__ == '__main__':
     init_db()
-    app.run(debug=True)
+    app.run(debug=False)
diff --git a/src/templates/404.html b/src/templates/404.html
new file mode 100644
index 0000000..7dddfb0
--- /dev/null
+++ b/src/templates/404.html
@@ -0,0 +1,4 @@
+{% extends 'base.html' %} {% block title %}404{% endblock %} {% block content %}
+<h1 class="bad-wrong">404</h1>
+<p>Page not found</p>
+{% endblock %}