diff --git a/ExamplesAndTests/Swordfish.NET.UnitTestV3/ConcurrentObservableSortedCollection_INotifyCollectionChangedTests.cs b/ExamplesAndTests/Swordfish.NET.UnitTestV3/ConcurrentObservableSortedCollection_INotifyCollectionChangedTests.cs
index bdb617d..6d9a0e6 100644
--- a/ExamplesAndTests/Swordfish.NET.UnitTestV3/ConcurrentObservableSortedCollection_INotifyCollectionChangedTests.cs
+++ b/ExamplesAndTests/Swordfish.NET.UnitTestV3/ConcurrentObservableSortedCollection_INotifyCollectionChangedTests.cs
@@ -76,7 +76,8 @@ public void Test_ConcurrentObservableSortedCollection_InsertRange()
 
             Assert.AreEqual(returnedObject, collection);
             Assert.AreEqual(NotifyCollectionChangedAction.Add, returnedArgs.Action);
-            Assert.AreEqual(startIndex, returnedArgs.NewStartingIndex);
+            // Sorted collection doesn't add at the index, so it should be -1
+            Assert.AreEqual(-1, returnedArgs.NewStartingIndex);
             Assert.IsNotNull(returnedArgs.NewItems);
             Assert.IsNull(returnedArgs.OldItems);
             Assert.AreEqual(toAdd.Count(), returnedArgs.NewItems.Count);
diff --git a/Swordfish.NET.CollectionsV3/ConcurrentObservableSortedCollection.cs b/Swordfish.NET.CollectionsV3/ConcurrentObservableSortedCollection.cs
index 1115087..d3778ff 100644
--- a/Swordfish.NET.CollectionsV3/ConcurrentObservableSortedCollection.cs
+++ b/Swordfish.NET.CollectionsV3/ConcurrentObservableSortedCollection.cs
@@ -50,10 +50,12 @@ public override void AddRange(IList<T> items)
 
         public override void Reset(IList<T> items) =>
             DoReadWriteNotify(
-              () => new OldAndNew(ImmutableList.ToArray(),items.OrderBy(x => x, _sorter).ToList()),
-              (oldAndNew) => ImmutableList<T>.Empty.AddRange(oldAndNew.New),
-              (oldAndNew) => new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, (IList)oldAndNew.Old, 0),
-              (oldAndNew) => new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, (IList)oldAndNew.New, 0)
+              // Sort the incoming collection and add it directly to the internal collection.
+              // Should be quicker than sorting 1 by 1 on insert.
+              () => ImmutableList.ToArray(),
+              (oldItems) => ImmutableList<T>.Empty.AddRange(items.OrderBy(x => x, _sorter).ToList()),
+              (oldItems) => new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, (IList)oldItems, 0),
+              (oldItems) => new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, (IList)items, 0)
             );
 
         public override void Insert(int index, T item)
@@ -75,16 +77,6 @@ public override T this[int index]
                 Add(value);
             }
         }
-
-        private class OldAndNew {
-            public OldAndNew(T[] old, List<T> @new)
-            {
-                Old = old;
-                New = @new;
-            }
-            public T[] Old;
-            public List<T> New;
-        }
     }
 }