diff --git a/ArchiSteamFarm/Bot.cs b/ArchiSteamFarm/Bot.cs
index d3fb3306f..493989887 100755
--- a/ArchiSteamFarm/Bot.cs
+++ b/ArchiSteamFarm/Bot.cs
@@ -816,7 +816,7 @@ namespace ArchiSteamFarm {
 						continue;
 					}
 
-					value.AppIDs = new HashSet<uint>();
+					value.AppIDs = new HashSet<uint>(appIDs.Children.Count);
 
 					foreach (string appIDText in appIDs.Children.Select(app => app.Value)) {
 						if (!uint.TryParse(appIDText, out uint appID) || (appID == 0)) {
diff --git a/ArchiSteamFarm/CardsFarmer.cs b/ArchiSteamFarm/CardsFarmer.cs
index 4705bfa07..0779ab93c 100755
--- a/ArchiSteamFarm/CardsFarmer.cs
+++ b/ArchiSteamFarm/CardsFarmer.cs
@@ -386,7 +386,7 @@ namespace ArchiSteamFarm {
 				return;
 			}
 
-			List<Task> backgroundTasks = null;
+			HashSet<Task> backgroundTasks = null;
 
 			foreach (HtmlNode htmlNode in htmlNodes) {
 				HtmlNode statsNode = htmlNode.SelectSingleNode(".//div[@class='badge_title_stats_content']");
@@ -671,7 +671,7 @@ namespace ArchiSteamFarm {
 							break;
 						default:
 							if (backgroundTasks == null) {
-								backgroundTasks = new List<Task>();
+								backgroundTasks = new HashSet<Task>();
 							}
 
 							backgroundTasks.Add(task);
@@ -1024,7 +1024,7 @@ namespace ArchiSteamFarm {
 
 					break;
 				default:
-					List<Task> tasks = new List<Task>(maxPages) { mainTask };
+					HashSet<Task> tasks = new HashSet<Task>(maxPages) { mainTask };
 
 					if (maxPages > 1) {
 						Bot.ArchiLogger.LogGenericInfo(Strings.CheckingOtherBadgePages);