diff --git a/AquaMai/Fix/DebugFeature.cs b/AquaMai/Fix/DebugFeature.cs
index 67d09f22..e9ec44ea 100644
--- a/AquaMai/Fix/DebugFeature.cs
+++ b/AquaMai/Fix/DebugFeature.cs
@@ -90,6 +90,7 @@ public class DebugFeature
 
     public static double CurrentPlayMsec
     {
+        [Obsolete("不要用它，它有问题。用 PractiseMode.CurrentPlayMsec")]
         get
         {
             if (IsPolyfill)
diff --git a/AquaMai/Utils/PractiseMode.cs b/AquaMai/Utils/PractiseMode.cs
index bcf3adfb..ac92981c 100644
--- a/AquaMai/Utils/PractiseMode.cs
+++ b/AquaMai/Utils/PractiseMode.cs
@@ -94,6 +94,26 @@ public class PractiseMode
         SetSpeed();
     }
 
+    public static void Seek(int addMsec)
+    {
+        // Debug feature 里面那个 timer 不能感知变速
+        // 为了和魔改版本统一，polyfill 里面不修这个
+        // 这里重新实现一个能感知变速的 Seek
+        var msec = CurrentPlayMsec + addMsec;
+        if (msec < 0)
+        {
+            msec = 0;
+        }
+
+        DebugFeature.CurrentPlayMsec = msec;
+    }
+
+    public static double CurrentPlayMsec
+    {
+        get => NotesManager.GetCurrentMsec() - 91;
+        set => DebugFeature.CurrentPlayMsec = value;
+    }
+
     public static PractiseModeUI ui;
 
     [HarmonyPatch(typeof(GameProcess), "OnStart")]
@@ -136,9 +156,9 @@ public class PractiseMode
 
         if (repeatStart >= 0 && repeatEnd >= 0)
         {
-            if (DebugFeature.CurrentPlayMsec >= repeatEnd)
+            if (CurrentPlayMsec >= repeatEnd)
             {
-                DebugFeature.CurrentPlayMsec = repeatStart;
+                CurrentPlayMsec = repeatStart;
             }
         }
     }
diff --git a/AquaMai/Utils/PractiseModeUI.cs b/AquaMai/Utils/PractiseModeUI.cs
index 12da7c10..2e107828 100644
--- a/AquaMai/Utils/PractiseModeUI.cs
+++ b/AquaMai/Utils/PractiseModeUI.cs
@@ -82,7 +82,7 @@ public class PractiseModeUI : MonoBehaviour
         GUI.Button(GetButtonRect(2, 2), Locale.SpeedUp);
         GUI.Button(GetButtonRect(1, 3), Locale.SpeedReset);
 
-        GUI.Label(GetButtonRect(0, 3), TimeSpan.FromMilliseconds(DebugFeature.CurrentPlayMsec).ToString(@"mm\:ss\.fff"));
+        GUI.Label(GetButtonRect(0, 3), TimeSpan.FromMilliseconds(PractiseMode.CurrentPlayMsec).ToString(@"mm\:ss\.fff"));
         GUI.Label(GetButtonRect(2, 3), TimeSpan.FromMilliseconds(NotesManager.Instance().getPlayFinalMsec()).ToString(@"mm\:ss\.fff"));
     }
 
@@ -90,12 +90,12 @@ public class PractiseModeUI : MonoBehaviour
     {
         if (InputManager.GetTouchPanelAreaDown(InputManager.TouchPanelArea.E8))
         {
-            DebugFeature.Seek(-1000);
+            PractiseMode.Seek(-1000);
             PractiseMode.SetSpeedCoroutine();
         }
         else if (InputManager.GetTouchPanelAreaDown(InputManager.TouchPanelArea.E2))
         {
-            DebugFeature.Seek(1000);
+            PractiseMode.Seek(1000);
             PractiseMode.SetSpeedCoroutine();
         }
         else if (InputManager.GetTouchPanelAreaDown(InputManager.TouchPanelArea.B8) || InputManager.GetTouchPanelAreaDown(InputManager.TouchPanelArea.B1))
@@ -103,17 +103,17 @@ public class PractiseModeUI : MonoBehaviour
             DebugFeature.Pause = !DebugFeature.Pause;
             if (!DebugFeature.Pause)
             {
-                DebugFeature.Seek(0);
+                PractiseMode.Seek(0);
                 PractiseMode.SetSpeedCoroutine();
             }
         }
         else if (InputManager.GetTouchPanelAreaDown(InputManager.TouchPanelArea.B7) && PractiseMode.repeatStart == -1)
         {
-            PractiseMode.repeatStart = DebugFeature.CurrentPlayMsec;
+            PractiseMode.repeatStart = PractiseMode.CurrentPlayMsec;
         }
         else if (InputManager.GetTouchPanelAreaDown(InputManager.TouchPanelArea.B7) && PractiseMode.repeatEnd == -1)
         {
-            PractiseMode.SetRepeatEnd(DebugFeature.CurrentPlayMsec);
+            PractiseMode.SetRepeatEnd(PractiseMode.CurrentPlayMsec);
         }
         else if (InputManager.GetTouchPanelAreaDown(InputManager.TouchPanelArea.B2))
         {