diff --git a/EduNetworkBuilder/NetworkCard.cs b/EduNetworkBuilder/NetworkCard.cs
index b55296d..4091244 100644
--- a/EduNetworkBuilder/NetworkCard.cs
+++ b/EduNetworkBuilder/NetworkCard.cs
@@ -671,7 +671,7 @@ namespace EduNetworkBuilder
             else
             {
                 tPacket.AddMessage(DebugLevel.routing,"The Packet was destined for a different machine (MAC Address): Rejected");
-                tPacket.AddMessage(DebugLevel.debug, "  Device MAC: " + MAC + "  did not match packet: " + tPacket.destMAC);
+                tPacket.AddMessage(DebugLevel.debug, string.Format("  Device MAC: {0} did not match packet: {1}", MAC, tPacket.destMAC));
                 mynet = NB.GetNetwork();
                 nd = mynet.GetDeviceFromID(myID);
                 string hostname = "No Host";