diff --git a/src/UniTask/Assets/Plugins/UniTask/Runtime/EnumeratorAsyncExtensions.cs b/src/UniTask/Assets/Plugins/UniTask/Runtime/EnumeratorAsyncExtensions.cs
index 7e3ebe7..831a3fc 100644
--- a/src/UniTask/Assets/Plugins/UniTask/Runtime/EnumeratorAsyncExtensions.cs
+++ b/src/UniTask/Assets/Plugins/UniTask/Runtime/EnumeratorAsyncExtensions.cs
@@ -32,6 +32,19 @@ namespace Cysharp.Threading.Tasks
             return new UniTask(EnumeratorPromise.Create(enumerator, timing, cancellationToken, out var token), token);
         }
 
+        public static UniTask ToUniTask(this IEnumerator enumerator, MonoBehaviour coroutineRunner)
+        {
+            var source = AutoResetUniTaskCompletionSource.Create();
+            coroutineRunner.StartCoroutine(Core(enumerator, coroutineRunner, source));
+            return source.Task;
+        }
+
+        static IEnumerator Core(IEnumerator inner, MonoBehaviour coroutineRunner, AutoResetUniTaskCompletionSource source)
+        {
+            yield return coroutineRunner.StartCoroutine(inner);
+            source.TrySetResult();
+        }
+
         sealed class EnumeratorPromise : IUniTaskSource, IPlayerLoopItem, ITaskPoolNode<EnumeratorPromise>
         {
             static TaskPool<EnumeratorPromise> pool;
@@ -215,7 +228,7 @@ namespace Cysharp.Threading.Tasks
                         }
                         else
                         {
-                            yield return null;
+                            goto WARN;
                         }
                     }
                     else if (current is IEnumerator e3)
@@ -228,9 +241,15 @@ namespace Cysharp.Threading.Tasks
                     }
                     else
                     {
-                        // WaitForEndOfFrame, WaitForFixedUpdate, others.
-                        yield return null;
+                        goto WARN;
                     }
+                    
+                    continue;
+
+                    WARN:
+                    // WaitForEndOfFrame, WaitForFixedUpdate, others.
+                    UnityEngine.Debug.LogWarning($"yield {current.GetType().Name} is not supported on await IEnumerator or IEnumerator.ToUniTask(), please use ToUniTask(MonoBehaviour coroutineRunner) instead.");
+                    yield return null;
                 }
             }
 
@@ -261,5 +280,4 @@ namespace Cysharp.Threading.Tasks
             }
         }
     }
-}
-
+}
\ No newline at end of file
diff --git a/src/UniTask/Assets/Scenes/SandboxMain.cs b/src/UniTask/Assets/Scenes/SandboxMain.cs
index 7fa0bf9..fbbc9a3 100644
--- a/src/UniTask/Assets/Scenes/SandboxMain.cs
+++ b/src/UniTask/Assets/Scenes/SandboxMain.cs
@@ -507,8 +507,19 @@ public class SandboxMain : MonoBehaviour
 
     CancellationTokenSource quitSource = new CancellationTokenSource();
 
+
+    IEnumerator TestCor()
+    {
+        Debug.Log("start cor");
+        yield return null;
+        yield return new WaitForEndOfFrame();
+        Debug.Log("end cor");
+    }
+
     async UniTaskVoid Start()
     {
+        await TestCor().ToUniTask(this);
+
         Debug.Log("App Start");
 
         Application.quitting += () =>