diff --git a/Assets/Scenes/SandboxMain.cs b/Assets/Scenes/SandboxMain.cs
index 1faf82d..0354ea9 100644
--- a/Assets/Scenes/SandboxMain.cs
+++ b/Assets/Scenes/SandboxMain.cs
@@ -14,13 +14,47 @@ public class SandboxMain : MonoBehaviour
     public Button cancelButton;
     CancellationTokenSource cts;
 
-    async void Start()
+    void Start()
     {
-        UnityEngine.Debug.Log("DOWNLOAD START:" + Time.frameCount);
-
-        var req = await UnityWebRequest.Get(Path.Combine(Application.streamingAssetsPath, "test.txt")).SendWebRequest();
-
-        UnityEngine.Debug.Log("DOWNLOAD RESULT:" + Time.frameCount + ", " + req.downloadHandler.text);
+        okButton.onClick.AddListener(() =>
+        {
+            FooAsync().Forget();
+        });
+        cancelButton.onClick.AddListener(() =>
+        {
+            BarAsync().Forget();
+        });
     }
+
+    async UniTask<int> FooAsync()
+    {
+        // use F10, will crash.
+        var loop = int.Parse("9");
+        await UniTask.DelayFrame(loop);
+
+        Debug.Log("OK");
+        await UniTask.DelayFrame(loop);
+
+        Debug.Log("Again");
+
+        return 10;
+    }
+
+    async UniTaskVoid BarAsync()
+    {
+        var loop = int.Parse("10");
+
+
+        var foo = await UniTask.FromResult(100);
+
+        Debug.Log("OK");
+
+
+        Debug.Log("Again");
+
+
+    }
+
+
 }
 
diff --git a/Assets/UniRx.Async/CompilerServices/AsyncUniTaskMethodBuilder.cs b/Assets/UniRx.Async/CompilerServices/AsyncUniTaskMethodBuilder.cs
index 586f859..76a358d 100644
--- a/Assets/UniRx.Async/CompilerServices/AsyncUniTaskMethodBuilder.cs
+++ b/Assets/UniRx.Async/CompilerServices/AsyncUniTaskMethodBuilder.cs
@@ -136,6 +136,22 @@ namespace UniRx.Async.CompilerServices
         public void SetStateMachine(IAsyncStateMachine stateMachine)
         {
         }
+
+#if UNITY_EDITOR
+        // Important for IDE debugger.
+        object debuggingId;
+        private object ObjectIdForDebugger 
+        {
+            get
+            {
+                if (debuggingId == null)
+                {
+                    debuggingId = new object();
+                }
+                return debuggingId; 
+            }
+        }
+#endif
     }
 
 
@@ -268,6 +284,22 @@ namespace UniRx.Async.CompilerServices
         public void SetStateMachine(IAsyncStateMachine stateMachine)
         {
         }
+
+#if UNITY_EDITOR
+        // Important for IDE debugger.
+        object debuggingId;
+        private object ObjectIdForDebugger
+        {
+            get
+            {
+                if (debuggingId == null)
+                {
+                    debuggingId = new object();
+                }
+                return debuggingId;
+            }
+        }
+#endif
     }
 }
 
diff --git a/Assets/UniRx.Async/CompilerServices/AsyncUniTaskVoidMethodBuilder.cs b/Assets/UniRx.Async/CompilerServices/AsyncUniTaskVoidMethodBuilder.cs
index 2fcd55f..bedf7bf 100644
--- a/Assets/UniRx.Async/CompilerServices/AsyncUniTaskVoidMethodBuilder.cs
+++ b/Assets/UniRx.Async/CompilerServices/AsyncUniTaskVoidMethodBuilder.cs
@@ -84,6 +84,22 @@ namespace UniRx.Async.CompilerServices
         public void SetStateMachine(IAsyncStateMachine stateMachine)
         {
         }
+
+#if UNITY_EDITOR
+        // Important for IDE debugger.
+        object debuggingId;
+        private object ObjectIdForDebugger
+        {
+            get
+            {
+                if (debuggingId == null)
+                {
+                    debuggingId = new object();
+                }
+                return debuggingId;
+            }
+        }
+#endif
     }
 }