diff --git a/ArchiSteamFarm/BotDatabase.cs b/ArchiSteamFarm/BotDatabase.cs
index ebfbd29e7..42c782859 100644
--- a/ArchiSteamFarm/BotDatabase.cs
+++ b/ArchiSteamFarm/BotDatabase.cs
@@ -20,7 +20,6 @@
 //  limitations under the License.
 
 using System;
-using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -30,7 +29,13 @@ using Newtonsoft.Json;
 
 namespace ArchiSteamFarm {
 	internal sealed class BotDatabase : IDisposable {
-		internal bool HasGamesToRedeemInBackground => GamesToRedeemInBackground.Count > 0;
+		internal bool HasGamesToRedeemInBackground {
+			get {
+				lock (GamesToRedeemInBackground) {
+					return GamesToRedeemInBackground.Count > 0;
+				}
+			}
+		}
 
 		[JsonProperty(Required = Required.DisallowNull)]
 		private readonly ConcurrentHashSet<ulong> BlacklistedFromTradesSteamIDs = new ConcurrentHashSet<ulong>();
@@ -38,7 +43,7 @@ namespace ArchiSteamFarm {
 		private readonly SemaphoreSlim FileSemaphore = new SemaphoreSlim(1, 1);
 
 		[JsonProperty(Required = Required.DisallowNull)]
-		private readonly ConcurrentDictionary<string, string> GamesToRedeemInBackground = new ConcurrentDictionary<string, string>();
+		private readonly SortedDictionary<string, string> GamesToRedeemInBackground = new SortedDictionary<string, string>();
 
 		[JsonProperty(Required = Required.DisallowNull)]
 		private readonly ConcurrentHashSet<uint> IdlingBlacklistedAppIDs = new ConcurrentHashSet<uint>();
@@ -87,8 +92,14 @@ namespace ArchiSteamFarm {
 				return;
 			}
 
-			// We use Count() and not Any() because we must ensure full loop pass
-			if (games.Count(game => GamesToRedeemInBackground.TryAdd(game.Key, game.Value)) > 0) {
+			bool save;
+
+			lock (GamesToRedeemInBackground) {
+				// We use Count() and not Any() because we must ensure full loop pass
+				save = games.Count(game => GamesToRedeemInBackground.TryAdd(game.Key, game.Value)) > 0;
+			}
+
+			if (save) {
 				await Save().ConfigureAwait(false);
 			}
 		}
@@ -99,7 +110,13 @@ namespace ArchiSteamFarm {
 				return;
 			}
 
-			if (GamesToRedeemInBackground.TryAdd(key, game)) {
+			bool save;
+
+			lock (GamesToRedeemInBackground) {
+				save = GamesToRedeemInBackground.TryAdd(key, game);
+			}
+
+			if (save) {
 				await Save().ConfigureAwait(false);
 			}
 		}
@@ -138,7 +155,13 @@ namespace ArchiSteamFarm {
 		}
 
 		internal IReadOnlyCollection<ulong> GetBlacklistedFromTradesSteamIDs() => BlacklistedFromTradesSteamIDs;
-		internal KeyValuePair<string, string> GetGameToRedeemInBackground() => GamesToRedeemInBackground.FirstOrDefault();
+
+		internal KeyValuePair<string, string> GetGameToRedeemInBackground() {
+			lock (GamesToRedeemInBackground) {
+				return GamesToRedeemInBackground.FirstOrDefault();
+			}
+		}
+
 		internal IReadOnlyCollection<uint> GetIdlingBlacklistedAppIDs() => IdlingBlacklistedAppIDs;
 		internal IReadOnlyCollection<uint> GetIdlingPriorityAppIDs() => IdlingPriorityAppIDs;
 
@@ -235,7 +258,13 @@ namespace ArchiSteamFarm {
 				return;
 			}
 
-			if (GamesToRedeemInBackground.Remove(key, out _)) {
+			bool save;
+
+			lock (GamesToRedeemInBackground) {
+				save = GamesToRedeemInBackground.Remove(key, out _);
+			}
+
+			if (save) {
 				await Save().ConfigureAwait(false);
 			}
 		}
diff --git a/ArchiSteamFarm/ConcurrentEnumerator.cs b/ArchiSteamFarm/ConcurrentEnumerator.cs
deleted file mode 100644
index 30056ebff..000000000
--- a/ArchiSteamFarm/ConcurrentEnumerator.cs
+++ /dev/null
@@ -1,51 +0,0 @@
-//     _                _      _  ____   _                           _____
-//    / \    _ __  ___ | |__  (_)/ ___| | |_  ___   __ _  _ __ ___  |  ___|__ _  _ __  _ __ ___
-//   / _ \  | '__|/ __|| '_ \ | |\___ \ | __|/ _ \ / _` || '_ ` _ \ | |_  / _` || '__|| '_ ` _ \
-//  / ___ \ | |  | (__ | | | || | ___) || |_|  __/| (_| || | | | | ||  _|| (_| || |   | | | | | |
-// /_/   \_\|_|   \___||_| |_||_||____/  \__|\___| \__,_||_| |_| |_||_|   \__,_||_|   |_| |_| |_|
-// 
-//  Copyright 2015-2018 Łukasz "JustArchi" Domeradzki
-//  Contact: JustArchi@JustArchi.net
-// 
-//  Licensed under the Apache License, Version 2.0 (the "License");
-//  you may not use this file except in compliance with the License.
-//  You may obtain a copy of the License at
-// 
-//  http://www.apache.org/licenses/LICENSE-2.0
-//      
-//  Unless required by applicable law or agreed to in writing, software
-//  distributed under the License is distributed on an "AS IS" BASIS,
-//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-//  See the License for the specific language governing permissions and
-//  limitations under the License.
-
-using System;
-using System.Collections;
-using System.Collections.Generic;
-using System.Threading;
-
-namespace ArchiSteamFarm {
-	internal sealed class ConcurrentEnumerator<T> : IEnumerator<T> {
-		public T Current => Enumerator.Current;
-
-		private readonly IEnumerator<T> Enumerator;
-		private readonly SemaphoreSlim SemaphoreSlim;
-
-		object IEnumerator.Current => Current;
-
-		internal ConcurrentEnumerator(IReadOnlyCollection<T> collection, SemaphoreSlim semaphoreSlim) {
-			if ((collection == null) || (semaphoreSlim == null)) {
-				throw new ArgumentNullException(nameof(collection) + " || " + nameof(semaphoreSlim));
-			}
-
-			SemaphoreSlim = semaphoreSlim;
-			SemaphoreSlim.Wait();
-
-			Enumerator = collection.GetEnumerator();
-		}
-
-		public void Dispose() => SemaphoreSlim.Release();
-		public bool MoveNext() => Enumerator.MoveNext();
-		public void Reset() => Enumerator.Reset();
-	}
-}
\ No newline at end of file
diff --git a/ArchiSteamFarm/ConcurrentSortedHashSet.cs b/ArchiSteamFarm/ConcurrentSortedHashSet.cs
index 364e790b8..0b7c13777 100644
--- a/ArchiSteamFarm/ConcurrentSortedHashSet.cs
+++ b/ArchiSteamFarm/ConcurrentSortedHashSet.cs
@@ -95,7 +95,7 @@ namespace ArchiSteamFarm {
 			}
 		}
 
-		public IEnumerator<T> GetEnumerator() => new ConcurrentEnumerator<T>(BackingCollection, CollectionSemaphore);
+		public IEnumerator<T> GetEnumerator() => new ConcurrentEnumerator(BackingCollection, CollectionSemaphore);
 
 		public void IntersectWith(IEnumerable<T> other) {
 			CollectionSemaphore.Wait();
@@ -213,5 +213,29 @@ namespace ArchiSteamFarm {
 				CollectionSemaphore.Release();
 			}
 		}
+
+		private sealed class ConcurrentEnumerator : IEnumerator<T> {
+			public T Current => Enumerator.Current;
+
+			private readonly IEnumerator<T> Enumerator;
+			private readonly SemaphoreSlim SemaphoreSlim;
+
+			object IEnumerator.Current => Current;
+
+			internal ConcurrentEnumerator(IReadOnlyCollection<T> collection, SemaphoreSlim semaphoreSlim) {
+				if ((collection == null) || (semaphoreSlim == null)) {
+					throw new ArgumentNullException(nameof(collection) + " || " + nameof(semaphoreSlim));
+				}
+
+				SemaphoreSlim = semaphoreSlim;
+				semaphoreSlim.Wait();
+
+				Enumerator = collection.GetEnumerator();
+			}
+
+			public void Dispose() => SemaphoreSlim.Release();
+			public bool MoveNext() => Enumerator.MoveNext();
+			public void Reset() => Enumerator.Reset();
+		}
 	}
 }
\ No newline at end of file