diff --git a/.editorconfig b/.editorconfig
index e50f5b5..4929470 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -29,3 +29,6 @@ dotnet_diagnostic.DV2001.severity = none
 
 # CS8602: Dereference of a possibly null reference.
 dotnet_diagnostic.CS8602.severity = silent
+
+# CS8714: The type cannot be used as type parameter in the generic type or method. Nullability of type argument doesn't match 'notnull' constraint.
+dotnet_diagnostic.CS8714.severity = none
diff --git a/Entities/ObservableDictionary.cs b/Entities/ObservableDictionary.cs
new file mode 100644
index 0000000..5cf8273
--- /dev/null
+++ b/Entities/ObservableDictionary.cs
@@ -0,0 +1,133 @@
+using System.Collections;
+using System.Diagnostics.CodeAnalysis;
+
+namespace Xorog.UniversalExtensions.Entities;
+
+public class ObservableDictionary<TKey, TValue> : IDictionary<TKey, TValue>
+{
+    private Dictionary<TKey, TValue> _items = new();
+
+    public event EventHandler<ObservableListUpdate<KeyValuePair<TKey, TValue>>> ItemsChanged = delegate { };
+
+    public TValue this[TKey key] { get => _items[key]; set => _items[key] = value; }
+
+    public ICollection<TKey> Keys => _items.Keys;
+
+    public ICollection<TValue> Values => _items.Values;
+
+    public int Count => _items.Count;
+
+    public bool IsReadOnly => false;
+
+    public void Add(TKey key, TValue value)
+    {
+        _items.Add(key, value);
+
+        _ = Task.Run(() =>
+        {
+            this.ItemsChanged.Invoke(null, new()
+            {
+                List = this.ToList(),
+                NewItems = new List<KeyValuePair<TKey, TValue>>() { new(key, value) },
+                RemovedItems = null
+            });
+        });
+    }
+
+    public void Add(KeyValuePair<TKey, TValue> item)
+    {
+        _items.Add(item.Key, item.Value);
+
+        _ = Task.Run(() =>
+        {
+            this.ItemsChanged.Invoke(null, new()
+            {
+                List = this.ToList(),
+                NewItems = new List<KeyValuePair<TKey, TValue>>() { new(item.Key, item.Value) },
+                RemovedItems = null
+            });
+        });
+    }
+
+    public void Clear()
+    {
+        var oldList = _items.ToList();
+        _items.Clear();
+
+        _ = Task.Run(() =>
+        {
+            this.ItemsChanged.Invoke(null, new()
+            {
+                List = this.ToList(),
+                NewItems = null,
+                RemovedItems = oldList
+            });
+        });
+    }
+
+    public bool Remove(TKey key)
+    {
+        var old = _items[key];
+        var v = _items.Remove(key);
+
+        _ = Task.Run(() =>
+        {
+            this.ItemsChanged.Invoke(null, new()
+            {
+                List = this.ToList(),
+                NewItems = null,
+                RemovedItems = new List<KeyValuePair<TKey, TValue>>() { new(key, old) },
+            });
+        });
+
+        return v;
+    }
+
+    public bool Remove(KeyValuePair<TKey, TValue> item)
+    {
+        var old = _items[item.Key];
+        var v = _items.Remove(item.Key);
+
+        _ = Task.Run(() =>
+        {
+            this.ItemsChanged.Invoke(null, new()
+            {
+                List = this.ToList(),
+                NewItems = null,
+                RemovedItems = new List<KeyValuePair<TKey, TValue>>() { new(item.Key, old) },
+            });
+        });
+        return v;
+    }
+
+    public void CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex)
+    {
+        List<KeyValuePair<TKey, TValue>> newArrayBuild = new();
+
+        for (var i = 0; i < array.Length; i++)
+        {
+            if (i == arrayIndex)
+                newArrayBuild.AddRange(this._items);
+
+            KeyValuePair<TKey, TValue> b = array[i];
+            newArrayBuild.Add(b);
+        }
+
+        array = newArrayBuild.ToArray();
+    }
+
+    public bool Contains(KeyValuePair<TKey, TValue> item)
+        => _items.Contains(item);
+
+    public bool ContainsKey(TKey key)
+        => _items.ContainsKey(key);
+
+    public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator()
+        => _items.GetEnumerator();
+
+    public bool TryGetValue(TKey key, [MaybeNullWhen(false)] out TValue value)
+        => _items.TryGetValue(key, out value);
+
+    IEnumerator IEnumerable.GetEnumerator()
+        => _items.GetEnumerator();
+}
diff --git a/Entities/ObservableList.cs b/Entities/ObservableList.cs
index 0c07a4f..fa519b8 100644
--- a/Entities/ObservableList.cs
+++ b/Entities/ObservableList.cs
@@ -22,7 +22,7 @@ public class ObservableList<T> : IList<T>
         {
             this.ItemsChanged.Invoke(null, new ObservableListUpdate<T>
             {
-                List = this,
+                List = this.ToList(),
                 NewItems = new List<T>() { item },
                 RemovedItems = null
             });
@@ -37,7 +37,7 @@ public class ObservableList<T> : IList<T>
         {
             this.ItemsChanged?.Invoke(null, new ObservableListUpdate<T>
             {
-                List = this,
+                List = this.ToList(),
                 NewItems = new List<T>() { item },
                 RemovedItems = null
             });
@@ -46,15 +46,16 @@ public class ObservableList<T> : IList<T>
 
     public void Clear()
     {
+        var oldList = _items.ToList();
         _items.Clear();
 
         _ = Task.Run(() =>
         {
             this.ItemsChanged?.Invoke(null, new ObservableListUpdate<T>
             {
-                List = this,
+                List = this.ToList(),
                 NewItems = null,
-                RemovedItems = _items.ToList()
+                RemovedItems = oldList
             });
         });
     }
@@ -63,7 +64,7 @@ public class ObservableList<T> : IList<T>
     {
         ObservableListUpdate<T> e = new ObservableListUpdate<T>
         {
-            List = this,
+            List = this.ToList(),
             NewItems = null,
             RemovedItems = new List<T>() { _items.ElementAt(index) }
         };
@@ -84,7 +85,7 @@ public class ObservableList<T> : IList<T>
         {
             this.ItemsChanged?.Invoke(null, new ObservableListUpdate<T>
             {
-                List = this,
+                List = this.ToList(),
                 NewItems = null,
                 RemovedItems = new List<T>() { item }
             });
diff --git a/Entities/ObservableListUpdate.cs b/Entities/ObservableListUpdate.cs
index 27e1f49..79dfee7 100644
--- a/Entities/ObservableListUpdate.cs
+++ b/Entities/ObservableListUpdate.cs
@@ -2,7 +2,7 @@
 
 public class ObservableListUpdate<T>
 {
-    public ObservableList<T>? List { get; internal set; }
+    public List<T>? List { get; internal set; }
 
     public IReadOnlyList<T>? NewItems { get; internal set; }
     public IReadOnlyList<T>? RemovedItems { get; internal set; }