diff --git a/src/UniTask/Assets/Plugins/UniTask/Runtime/CancellationTokenExtensions.cs b/src/UniTask/Assets/Plugins/UniTask/Runtime/CancellationTokenExtensions.cs
index d7cd06b..c139acc 100644
--- a/src/UniTask/Assets/Plugins/UniTask/Runtime/CancellationTokenExtensions.cs
+++ b/src/UniTask/Assets/Plugins/UniTask/Runtime/CancellationTokenExtensions.cs
@@ -18,11 +18,32 @@ namespace Cysharp.Threading.Tasks
             return cts.Token;
         }
 
-        public static CancellationToken ToCancellationToken<T>(this UniTask<T> task)
+        public static CancellationToken ToCancellationToken(this UniTask task, CancellationToken linkToken)
         {
+            if (linkToken.IsCancellationRequested)
+            {
+                return linkToken;
+            }
+
+            if (!linkToken.CanBeCanceled)
+            {
+                return ToCancellationToken(task);
+            }
+
             var cts = new CancellationTokenSource();
             ToCancellationTokenCore(task, cts).Forget();
-            return cts.Token;
+
+            return CancellationTokenSource.CreateLinkedTokenSource(linkToken).Token;
+        }
+
+        public static CancellationToken ToCancellationToken<T>(this UniTask<T> task)
+        {
+            return ToCancellationToken(task.AsUniTask());
+        }
+
+        public static CancellationToken ToCancellationToken<T>(this UniTask<T> task, CancellationToken linkToken)
+        {
+            return ToCancellationToken(task.AsUniTask(), linkToken);
         }
 
         static async UniTaskVoid ToCancellationTokenCore(UniTask task, CancellationTokenSource cts)
diff --git a/src/UniTask/Assets/Scenes/SandboxMain.cs b/src/UniTask/Assets/Scenes/SandboxMain.cs
index 2f2b0bb..d75fb3e 100644
--- a/src/UniTask/Assets/Scenes/SandboxMain.cs
+++ b/src/UniTask/Assets/Scenes/SandboxMain.cs
@@ -434,16 +434,31 @@ public class SandboxMain : MonoBehaviour
         throw new Exception("yeah");
     }
 
-    
 
 
-    void Start()
+
+    async UniTaskVoid Start()
     {
-        _ = Foo(); // unhandled.
-        Go();
+        //_ = Foo(); // unhandled.
+        //Go();
+        var cts = new CancellationTokenSource();
+
+        okButton.onClick.AddListener(() =>
+        {
+            cts.Cancel();
+        });
+
 
         UnityEngine.Debug.Log("Start:" + PlayerLoopInfo.CurrentLoopType);
 
+        var token = UniTask.Delay(TimeSpan.FromSeconds(3), DelayType.Realtime).ToCancellationToken(cts.Token);
+        while (!token.IsCancellationRequested)
+        {
+            UnityEngine.Debug.Log("in loop");
+            await UniTask.Yield();
+        }
+        UnityEngine.Debug.Log("end");
+
 
         // this.GetCancellationTokenOnDestroy()
 
diff --git a/src/UniTask/Assets/Tests/DelayTest.cs b/src/UniTask/Assets/Tests/DelayTest.cs
index 25de6e2..7102f4e 100644
--- a/src/UniTask/Assets/Tests/DelayTest.cs
+++ b/src/UniTask/Assets/Tests/DelayTest.cs
@@ -190,7 +190,7 @@ namespace Cysharp.Threading.TasksTests
         {
             var now = DateTimeOffset.UtcNow;
 
-            await UniTask.DelayRealtime(TimeSpan.FromSeconds(2));
+            await UniTask.Delay(TimeSpan.FromSeconds(2), DelayType.Realtime);
 
             var elapsed = DateTimeOffset.UtcNow - now;