diff --git a/OpenRA.Game/Network/UPnP.cs b/OpenRA.Game/Network/UPnP.cs
index e05c4f26a5..97e61fe5d3 100644
--- a/OpenRA.Game/Network/UPnP.cs
+++ b/OpenRA.Game/Network/UPnP.cs
@@ -42,7 +42,7 @@ namespace OpenRA.Network
 			Log.Write("server", "Stopping NAT discovery.");
 			NatUtility.StopDiscovery();
 
-			if (NatDevice == null)
+			if (NatDevice == null || NatDevice.GetType() != typeof(Mono.Nat.Upnp.UpnpNatDevice))
 			{
 				Log.Write("server", "No NAT devices with UPnP enabled found within {0} ms deadline. Disabling automatic port forwarding.".F(Game.Settings.Server.NatDiscoveryTimeout));
 				Game.Settings.Server.NatDeviceAvailable = false;