diff --git a/meshtastic/__main__.py b/meshtastic/__main__.py
index 1d0c2480..3d6616d0 100644
--- a/meshtastic/__main__.py
+++ b/meshtastic/__main__.py
@@ -771,7 +771,10 @@ def setSimpleConfig(modem_preset):
             if interface.noProto:
                 logging.warning(f"Not starting Tunnel - disabled by noProto")
             else:
-                tunnel.Tunnel(interface, subnet=args.tunnel_net)
+                if args.tunnel_net:
+                    tunnel.Tunnel(interface, subnet=args.tunnel_net)
+                else:
+                    tunnel.Tunnel(interface)
 
         if args.ack or (args.dest != BROADCAST_ADDR and waitForAckNak):
             print(
diff --git a/meshtastic/tunnel.py b/meshtastic/tunnel.py
index b880efab..b3fe7d4f 100644
--- a/meshtastic/tunnel.py
+++ b/meshtastic/tunnel.py
@@ -49,6 +49,12 @@ def __init__(self, iface, subnet="10.115", netmask="255.255.0.0"):
         if not iface:
             raise Exception("Tunnel() must have a interface")
 
+        if not subnet:
+            raise Exception("Tunnel() must have a subnet")
+
+        if not netmask:
+            raise Exception("Tunnel() must have a netmask")
+
         self.iface = iface
         self.subnetPrefix = subnet