diff --git a/Lawo.EmberPlusSharp/Model/CollectionNode`2.cs b/Lawo.EmberPlusSharp/Model/CollectionNode`2.cs
index e2fb1d8a..37f8be6b 100644
--- a/Lawo.EmberPlusSharp/Model/CollectionNode`2.cs
+++ b/Lawo.EmberPlusSharp/Model/CollectionNode`2.cs
@@ -62,7 +62,12 @@ internal sealed override bool ChangeVisibility(IElement child)
             {
                 if (child.IsOnline)
                 {
-                    this.children.Add((TElement)child);
+                    var typedChild = (TElement)child;
+
+                    if (!this.children.Contains(typedChild))
+                    {
+                        this.children.Add(typedChild);
+                    }
                 }
                 else
                 {
diff --git a/Lawo.EmberPlusSharp/Model/DynamicNodeHelper.cs b/Lawo.EmberPlusSharp/Model/DynamicNodeHelper.cs
index a9831479..0c7df615 100644
--- a/Lawo.EmberPlusSharp/Model/DynamicNodeHelper.cs
+++ b/Lawo.EmberPlusSharp/Model/DynamicNodeHelper.cs
@@ -37,7 +37,10 @@ internal static bool ChangeVisibility(
             {
                 if (child.IsOnline)
                 {
-                    dynamicChildren.Add(child);
+                    if (!dynamicChildren.Contains(child))
+                    {
+                        dynamicChildren.Add(child);
+                    }
                 }
                 else
                 {
diff --git a/Lawo.EmberPlusSharp/Model/Node`1.cs b/Lawo.EmberPlusSharp/Model/Node`1.cs
index 8039c23b..a7ad9e48 100644
--- a/Lawo.EmberPlusSharp/Model/Node`1.cs
+++ b/Lawo.EmberPlusSharp/Model/Node`1.cs
@@ -62,7 +62,10 @@ internal override bool ChangeVisibility(IElement child)
         {
             if (child.IsOnline)
             {
-                this.observableChildren.Add(child);
+                if (!this.observableChildren.Contains(child))
+                {
+                    this.observableChildren.Add(child);
+                }
             }
             else
             {
diff --git a/Lawo.EmberPlusSharpTest/Model/ConsumerTest.cs b/Lawo.EmberPlusSharpTest/Model/ConsumerTest.cs
index 7a04c789..87802b74 100644
--- a/Lawo.EmberPlusSharpTest/Model/ConsumerTest.cs
+++ b/Lawo.EmberPlusSharpTest/Model/ConsumerTest.cs
@@ -1393,35 +1393,6 @@ public void Bug27Test()
                 "false"));
         }
 
-        /// <summary>Exposes <see href="https://github.com/Lawo/ember-plus-sharp/issues/33">Bug 33</see>.</summary>
-        [TestMethod]
-        [TestCategory("Manual")]
-        public void Bug33Test()
-        {
-            AsyncPump.Run(async () =>
-            {
-                var tcpClient = new TcpClient();
-                await tcpClient.ConnectAsync("localhost", 9000);
-                var stream = tcpClient.GetStream();
-                using (var client = new S101Client(tcpClient, stream.ReadAsync, stream.WriteAsync))
-                using (var consumer =
-                    await Consumer<EmptyDynamicRoot>.CreateAsync(client, 10000, ChildrenRetrievalPolicy.DirectOnly))
-                {
-                    foreach (var child in consumer.Root.DynamicChildren)
-                    {
-                        var node = child as INode;
-
-                        if (node != null)
-                        {
-                            node.ChildrenRetrievalPolicy = ChildrenRetrievalPolicy.DirectOnly;
-                        }
-                    }
-
-                    await consumer.SendAsync();
-                }
-            });
-        }
-
         ////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
         private static Task TestConsumerAfterFirstRequest<TRoot>(
@@ -2003,13 +1974,16 @@ private Task DynamicChildrenRetrievalPolicyTestAsync(bool delay)
                         consumer.AutoSendInterval = this.Random.Next(100, 5000);
                         var root = consumer.Root;
                         Assert.IsNull(root.Node);
+                        Assert.AreEqual(0, ((INode)root).Children.Count);
                         Assert.AreEqual(ChildrenRetrievalPolicy.None, root.ChildrenRetrievalPolicy);
                         root.ChildrenRetrievalPolicy = ChildrenRetrievalPolicy.DirectOnly;
                         await WaitForCompletion(consumer, delay);
                         Assert.IsNotNull(root.Node);
+                        Assert.AreEqual(1, ((INode)root).Children.Count);
                         Assert.AreEqual(ChildrenRetrievalPolicy.None, root.Node.ChildrenRetrievalPolicy);
                         root.Node.ChildrenRetrievalPolicy = ChildrenRetrievalPolicy.All;
                         await WaitForCompletion(consumer, delay);
+                        Assert.AreEqual(1, ((INode)root).Children.Count);
                     }
                 },
                 null,