diff --git a/Makefile b/Makefile
index ca30b7f..a1d2549 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ PYTHON=python3
 
 .PHONY: run
 run: templates/S2_perm_sw.html templates/S4_server.py venv static/i-ico.png static/i-banner.png
-	($(VENVACT) && python templates/S4_server.py )
+	($(VENVACT) && python templates/S4_server.py $(PORT) )
 
 VENVACT=. ./venv/bin/activate
 
diff --git a/src/S4_server.py b/src/S4_server.py
index 13f78c0..632c9ac 100644
--- a/src/S4_server.py
+++ b/src/S4_server.py
@@ -3,6 +3,7 @@
 from flask import Flask, render_template, request, make_response, send_from_directory
 from pywebpush import webpush, WebPushException
 import json
+import sys
 import time
 import threading
 
@@ -90,4 +91,6 @@ def push():
 
 # (C) START
 if __name__ == "__main__":
+  if len(sys.argv) == 2:
+    HOST_PORT = int(sys.argv[1])
   app.run(HOST_NAME, HOST_PORT)