diff --git a/srv/poe_manager/app.py b/srv/poe_manager/app.py
index b00e1a2..8301f7b 100644
--- a/srv/poe_manager/app.py
+++ b/srv/poe_manager/app.py
@@ -216,7 +216,7 @@ def devices():
             old_mac = request.form.get('old_mac')
             mac = request.form.get('mac')
             rpi_ip = request.form.get('rpi_ip')
-            port = request.form.get('port')
+            port = request.form.get('port') or None
             name = request.form.get('name')
             switch_hostname = request.form.get('switch_hostname') or None
             is_active = 1 if 'is_active' in request.form else 0
@@ -245,7 +245,7 @@ def devices():
                     flash("Fehler beim Ändern des Switch!")
                 return redirect(url_for('devices'))
 
-                if not all([old_mac, mac, rpi_ip, port, name]):
+                if not all([old_mac, mac, rpi_ip, name]):
                     flash("Alle Felder müssen ausgefüllt sein!")
                     return redirect(url_for('devices'))