diff --git a/ArchiSteamFarm/Bot.cs b/ArchiSteamFarm/Bot.cs
index b8586f58b..0eeb3ab60 100755
--- a/ArchiSteamFarm/Bot.cs
+++ b/ArchiSteamFarm/Bot.cs
@@ -610,6 +610,8 @@ namespace ArchiSteamFarm {
 
 			// Remove from our pending inventory all items that are not steam cards and boosters
 			inventory.RemoveWhere(item => item.Type != Steam.Item.EType.TradingCard && item.Type != Steam.Item.EType.FoilTradingCard && item.Type != Steam.Item.EType.BoosterPack);
+			inventory.TrimExcess();
+
 			if (inventory.Count == 0) {
 				return "Nothing to send, inventory seems empty!";
 			}
diff --git a/ArchiSteamFarm/Trading.cs b/ArchiSteamFarm/Trading.cs
index e5dae8e87..75792e39a 100644
--- a/ArchiSteamFarm/Trading.cs
+++ b/ArchiSteamFarm/Trading.cs
@@ -173,6 +173,7 @@ namespace ArchiSteamFarm {
 
 			// Now remove from our inventory all items we're NOT interested in
 			inventory.RemoveWhere(item => !appIDs.Contains(item.RealAppID));
+			inventory.TrimExcess();
 
 			// If for some reason Valve is talking crap and we can't find mentioned items, assume OK
 			if (inventory.Count == 0) {
diff --git a/ArchiSteamFarm/WCF.cs b/ArchiSteamFarm/WCF.cs
index 07a3f3c23..1f7b071ba 100644
--- a/ArchiSteamFarm/WCF.cs
+++ b/ArchiSteamFarm/WCF.cs
@@ -122,8 +122,13 @@ namespace ArchiSteamFarm {
 
 			Logging.LogGenericInfo("Received command: " + input);
 
-			string command = '!' + input;
-			string output = bot.Response(Program.GlobalConfig.SteamOwnerID, command).Result; // TODO: This should be asynchronous
+			string output;
+			if (Program.GlobalConfig.SteamOwnerID == 0) {
+				output = "Refusing to handle request because SteamOwnerID is not set!";
+			} else {
+				string command = '!' + input;
+				output = bot.Response(Program.GlobalConfig.SteamOwnerID, command).Result; // TODO: This should be asynchronous
+			}
 
 			Logging.LogGenericInfo("Answered to command: " + input + " with: " + output);
 			return output;