diff --git a/Source/Collections/Constants.cs b/Source/Collections/Constants.cs
index 202a3ff..6af5251 100644
--- a/Source/Collections/Constants.cs
+++ b/Source/Collections/Constants.cs
@@ -19,16 +19,20 @@ License along with this library
 #endregion
 
 using System;
+#if !NO_SPECIALIZED_COLLECTIONS
 using System.Collections.Specialized;
+#endif
 
 namespace Nuclex.Support.Collections {
 
   /// <summary>Contains fixed constants used by some collections</summary>
   public static class Constants {
 
+#if !NO_SPECIALIZED_COLLECTIONS
     /// <summary>Fixed event args used to notify that the collection has reset</summary>
     public static readonly NotifyCollectionChangedEventArgs NotifyCollectionResetEventArgs =
       new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset);
+#endif
 
   }
 
diff --git a/Source/Collections/ObservableDictionary.Test.cs b/Source/Collections/ObservableDictionary.Test.cs
index 39c3d77..16c709c 100644
--- a/Source/Collections/ObservableDictionary.Test.cs
+++ b/Source/Collections/ObservableDictionary.Test.cs
@@ -60,6 +60,13 @@ namespace Nuclex.Support.Collections {
       /// <param name="arguments">Contains the item that is being removed</param>
       void ItemRemoved(object sender, ItemEventArgs<KeyValuePair<int, string>> arguments);
 
+      /// <summary>Called when an item is replaced in the dictionary</summary>
+      /// <param name="sender">Dictionary in which an item is being replaced</param>
+      /// <param name="arguments">Contains the replaced item and its replacement</param>
+      void ItemReplaced(
+        object sender, ItemReplaceEventArgs<KeyValuePair<int, string>> arguments
+      );
+
     }
 
     #endregion // interface IObservableDictionarySubscriber
@@ -89,6 +96,10 @@ namespace Nuclex.Support.Collections {
         new EventHandler<ItemEventArgs<KeyValuePair<int, string>>>(
           this.mockedSubscriber.MockObject.ItemRemoved
         );
+      this.observedDictionary.ItemReplaced +=
+        new EventHandler<ItemReplaceEventArgs<KeyValuePair<int, string>>>(
+          this.mockedSubscriber.MockObject.ItemReplaced
+        );
     }
 
     /// <summary>
@@ -288,11 +299,9 @@ namespace Nuclex.Support.Collections {
     [Test]
     public void TestReplaceByIndexerViaGenericIDictionary() {
       this.mockedSubscriber.Expects.One.Method(
-        m => m.ItemRemoved(null, null)
-      ).WithAnyArguments();
-      this.mockedSubscriber.Expects.One.Method(
-        m => m.ItemAdded(null, null)
+        m => m.ItemReplaced(null, null)
       ).WithAnyArguments();
+
       (this.observedDictionary as IDictionary<int, string>)[42] = "two and fourty";
       this.mockery.VerifyAllExpectationsHaveBeenMet();
 
diff --git a/Source/Collections/ObservableList.Test.cs b/Source/Collections/ObservableList.Test.cs
index 30fb4b5..f95bcd9 100644
--- a/Source/Collections/ObservableList.Test.cs
+++ b/Source/Collections/ObservableList.Test.cs
@@ -57,6 +57,11 @@ namespace Nuclex.Support.Collections {
       /// <param name="arguments">Contains the item that is being removed</param>
       void ItemRemoved(object sender, ItemEventArgs<int> arguments);
 
+      /// <summary>Called when an item is replaced in the dictionary</summary>
+      /// <param name="sender">Dictionary in which an item is being replaced</param>
+      /// <param name="arguments">Contains the replaced item and its replacement</param>
+      void ItemReplaced(object sender, ItemReplaceEventArgs<int> arguments);
+
     }
 
     #endregion // interface IObservableCollectionSubscriber
@@ -81,6 +86,9 @@ namespace Nuclex.Support.Collections {
       this.observedList.ItemRemoved += new EventHandler<ItemEventArgs<int>>(
         this.mockedSubscriber.MockObject.ItemRemoved
       );
+      this.observedList.ItemReplaced += new EventHandler<ItemReplaceEventArgs<int>>(
+        this.mockedSubscriber.MockObject.ItemReplaced
+      );
     }
 
     /// <summary>Tests whether the Clearing event is fired</summary>
@@ -128,8 +136,7 @@ namespace Nuclex.Support.Collections {
       this.observedList.Add(2);
       this.observedList.Add(3);
 
-      this.mockedSubscriber.Expects.One.Method(m => m.ItemRemoved(null, null)).WithAnyArguments();
-      this.mockedSubscriber.Expects.One.Method(m => m.ItemAdded(null, null)).WithAnyArguments();
+      this.mockedSubscriber.Expects.One.Method(m => m.ItemReplaced(null, null)).WithAnyArguments();
 
       // Replace the middle item with something else
       this.observedList[1] = 4;