diff --git a/src/Framework/Framework/Controls/Repeater.cs b/src/Framework/Framework/Controls/Repeater.cs
index c6a3073be1..ccc4cf5f87 100644
--- a/src/Framework/Framework/Controls/Repeater.cs
+++ b/src/Framework/Framework/Controls/Repeater.cs
@@ -10,6 +10,7 @@
 using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Collections.Generic;
+using DotVVM.Framework.Utils;
 
 namespace DotVVM.Framework.Controls
 {
@@ -139,6 +140,7 @@ protected internal override void OnLoad(IDotvvmRequestContext context)
         protected internal override void OnPreRender(IDotvvmRequestContext context)
         {
             SetChildren(context, renderClientTemplate: !RenderOnServer, memoizeReferences: false);
+            childrenCache.Clear(); // not going to need the unreferenced children anymore
             base.OnPreRender(context);
         }
 
@@ -248,7 +250,7 @@ private DotvvmControl CreateEmptyItem(IDotvvmRequestContext context)
             return emptyDataContainer;
         }
 
-        private ConditionalWeakTable<object, DataItemContainer> childrenCache = new ConditionalWeakTable<object, DataItemContainer>();
+        private readonly Dictionary<object, DataItemContainer> childrenCache = new(ReferenceEqualityComparer<object>.Instance);
         private DotvvmControl AddItem(IList<DotvvmControl> c, IDotvvmRequestContext context, object? item = null, int? index = null, bool allowMemoizationRetrieve = false, bool allowMemoizationStore = false)
         {
             if (allowMemoizationRetrieve && item != null && childrenCache.TryGetValue(item, out var container2) && container2.Parent == null)
@@ -276,8 +278,12 @@ private DotvvmControl AddItem(IList<DotvvmControl> c, IDotvvmRequestContext cont
             // write it to the cache after the content is build. If it would be before that, exception could be suppressed
             if (allowMemoizationStore && item != null)
             {
-                // this GetValue call adds the value without raising exception when the value is already added...
-                childrenCache.GetValue(item, _ => container);
+#if DotNetCore
+                childrenCache.TryAdd(item, container);
+#else
+                if (!childrenCache.ContainsKey(item))
+                    childrenCache.Add(item, container);
+#endif
             }
 
             return container;
@@ -306,6 +312,7 @@ private void SetChildren(IDotvvmRequestContext context, bool renderClientTemplat
             if (DataSource != null)
             {
                 var index = 0;
+                var isCommand = context.RequestType == DotvvmRequestType.Command; // on GET request we are not initializing the Repeater twice
                 foreach (var item in GetIEnumerableFromDataSource()!)
                 {
                     if (SeparatorTemplate != null && index > 0)
@@ -313,7 +320,7 @@ private void SetChildren(IDotvvmRequestContext context, bool renderClientTemplat
                         AddSeparator(Children, context);
                     }
                     AddItem(Children, context, item, index,
-                        allowMemoizationRetrieve: context.RequestType == DotvvmRequestType.Command && !memoizeReferences, // on GET request we are not initializing the Repeater twice
+                        allowMemoizationRetrieve: isCommand && !memoizeReferences,
                         allowMemoizationStore: memoizeReferences
                     );
                     index++;
diff --git a/src/Framework/Framework/Utils/ReferenceEqualityComparer.cs b/src/Framework/Framework/Utils/ReferenceEqualityComparer.cs
new file mode 100644
index 0000000000..4c34d41263
--- /dev/null
+++ b/src/Framework/Framework/Utils/ReferenceEqualityComparer.cs
@@ -0,0 +1,16 @@
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+
+namespace DotVVM.Framework.Utils
+{
+    // TODO next version: Replace with System.Collections.Generic.ReferenceEqualityComparer
+    internal class ReferenceEqualityComparer<T> : IEqualityComparer<T>
+        where T : class
+    {
+        public static ReferenceEqualityComparer<T> Instance { get; } = new ReferenceEqualityComparer<T>();
+
+
+        public bool Equals(T? x, T? y) => ReferenceEquals(x, y);
+        public int GetHashCode(T obj) => obj == null ? 0 : RuntimeHelpers.GetHashCode(obj);
+    }
+}