diff --git a/ArchiSteamFarm/Collections/ConcurrentEnumerator.cs b/ArchiSteamFarm/Collections/ConcurrentEnumerator.cs
new file mode 100644
index 000000000..66bc62e69
--- /dev/null
+++ b/ArchiSteamFarm/Collections/ConcurrentEnumerator.cs
@@ -0,0 +1,52 @@
+//     _                _      _  ____   _                           _____
+//    / \    _ __  ___ | |__  (_)/ ___| | |_  ___   __ _  _ __ ___  |  ___|__ _  _ __  _ __ ___
+//   / _ \  | '__|/ __|| '_ \ | |\___ \ | __|/ _ \ / _` || '_ ` _ \ | |_  / _` || '__|| '_ ` _ \
+//  / ___ \ | |  | (__ | | | || | ___) || |_|  __/| (_| || | | | | ||  _|| (_| || |   | | | | | |
+// /_/   \_\|_|   \___||_| |_||_||____/  \__|\___| \__,_||_| |_| |_||_|   \__,_||_|   |_| |_| |_|
+// |
+// Copyright 2015-2019 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;
+using JetBrains.Annotations;
+
+namespace ArchiSteamFarm.Collections {
+	internal sealed class ConcurrentEnumerator<T> : IEnumerator<T> {
+		public T Current => Enumerator.Current;
+
+		private readonly IEnumerator<T> Enumerator;
+		private readonly SemaphoreSlim Semaphore;
+
+		object IEnumerator.Current => Current;
+
+		internal ConcurrentEnumerator([NotNull] IReadOnlyCollection<T> collection, [NotNull] SemaphoreSlim semaphore) {
+			if ((collection == null) || (semaphore == null)) {
+				throw new ArgumentNullException(nameof(collection) + " || " + nameof(semaphore));
+			}
+
+			Semaphore = semaphore;
+			semaphore.Wait();
+
+			Enumerator = collection.GetEnumerator();
+		}
+
+		public void Dispose() => Semaphore.Release();
+		public bool MoveNext() => Enumerator.MoveNext();
+		public void Reset() => Enumerator.Reset();
+	}
+}
diff --git a/ArchiSteamFarm/Collections/ConcurrentSortedHashSet.cs b/ArchiSteamFarm/Collections/ConcurrentSortedHashSet.cs
index 0bc5c0671..6386e1080 100644
--- a/ArchiSteamFarm/Collections/ConcurrentSortedHashSet.cs
+++ b/ArchiSteamFarm/Collections/ConcurrentSortedHashSet.cs
@@ -97,7 +97,7 @@ namespace ArchiSteamFarm.Collections {
 			}
 		}
 
-		public IEnumerator<T> GetEnumerator() => new ConcurrentEnumerator(BackingCollection, CollectionSemaphore);
+		public IEnumerator<T> GetEnumerator() => new ConcurrentEnumerator<T>(BackingCollection, CollectionSemaphore);
 
 		public void IntersectWith(IEnumerable<T> other) {
 			CollectionSemaphore.Wait();
@@ -217,29 +217,5 @@ namespace ArchiSteamFarm.Collections {
 				CollectionSemaphore.Release();
 			}
 		}
-
-		private sealed class ConcurrentEnumerator : IEnumerator<T> {
-			public T Current => Enumerator.Current;
-
-			private readonly IEnumerator<T> Enumerator;
-			private readonly SemaphoreSlim Semaphore;
-
-			object IEnumerator.Current => Current;
-
-			internal ConcurrentEnumerator([NotNull] IReadOnlyCollection<T> collection, [NotNull] SemaphoreSlim semaphore) {
-				if ((collection == null) || (semaphore == null)) {
-					throw new ArgumentNullException(nameof(collection) + " || " + nameof(semaphore));
-				}
-
-				Semaphore = semaphore;
-				semaphore.Wait();
-
-				Enumerator = collection.GetEnumerator();
-			}
-
-			public void Dispose() => Semaphore.Release();
-			public bool MoveNext() => Enumerator.MoveNext();
-			public void Reset() => Enumerator.Reset();
-		}
 	}
 }