diff --git a/app.py b/app.py
index e4410e8..00b1d04 100644
--- a/app.py
+++ b/app.py
@@ -5,8 +5,6 @@ from icalendar.cal import Calendar, Component
 
 app = Flask(__name__)
 
-port = int(os.environ.get('PORT', 33507))
-
 
 @app.route("/")
 def hello():
@@ -47,4 +45,5 @@ def hello():
     return other.to_ical().replace(b'\r\n', b'\n').strip()
 
 if __name__ == "__main__":
-    app.run(port=port)
+    port = int(os.environ.get('PORT', 5000))
+    app.run('0.0.0.0', port)