diff --git a/src/main/java/com/github/zly2006/reden/access/PlayerData.kt b/src/main/java/com/github/zly2006/reden/access/PlayerData.kt
index 5b6b9e2c..4bb78d83 100644
--- a/src/main/java/com/github/zly2006/reden/access/PlayerData.kt
+++ b/src/main/java/com/github/zly2006/reden/access/PlayerData.kt
@@ -73,6 +73,11 @@ class PlayerData(
                             .expand(0.1),
                     ) { x -> x !is PlayerEntity && x !is TntEntity }
                     list.forEach { entity ->
+                        if (lastThread == null) lastThread = Thread.currentThread()
+                        else if (lastThread!!.id != Thread.currentThread().id) {
+                            println("aaaaaaaaaaa")
+                            throw IllegalStateException("Not thread safe")
+                        }
                         entities.computeIfAbsent(entity.uuid) {
                             EntityEntry(entity.type, NbtCompound().apply(entity::writeNbt), entity.blockPos)
                         }
@@ -106,3 +111,5 @@ class PlayerData(
         val pos: BlockPos
     )
 }
+
+var lastThread: Thread? = null
\ No newline at end of file
diff --git a/src/main/java/com/github/zly2006/reden/mixin/undo/MixinMovingPiston.java b/src/main/java/com/github/zly2006/reden/mixin/undo/MixinMovingPiston.java
index 9e04cc6b..92745126 100644
--- a/src/main/java/com/github/zly2006/reden/mixin/undo/MixinMovingPiston.java
+++ b/src/main/java/com/github/zly2006/reden/mixin/undo/MixinMovingPiston.java
@@ -2,9 +2,9 @@
 
 import com.github.zly2006.reden.access.UndoableAccess;
 import com.github.zly2006.reden.mixinhelper.UpdateMonitorHelper;
+import com.github.zly2006.reden.utils.DebugKt;
 import net.minecraft.block.BlockState;
 import net.minecraft.block.PistonExtensionBlock;
-import net.minecraft.block.entity.BlockEntity;
 import net.minecraft.block.entity.BlockEntityTicker;
 import net.minecraft.block.entity.BlockEntityType;
 import net.minecraft.block.entity.PistonBlockEntity;
@@ -21,13 +21,22 @@ public class MixinMovingPiston {
      */
     @Overwrite
     @Nullable
-    public <T extends BlockEntity> BlockEntityTicker<T> getTicker(World world, BlockState state, BlockEntityType<T> type) {
+    public <T extends PistonBlockEntity> BlockEntityTicker<T> getTicker(World world, BlockState state, BlockEntityType<T> type) {
         return (type == BlockEntityType.PISTON) ? (world1, pos, state1, be) -> {
-            if (be instanceof UndoableAccess access) {
-                UpdateMonitorHelper.INSTANCE.setRecording(UpdateMonitorHelper.INSTANCE.getUndoRecordsMap().get(access.getUndoId()));
+            boolean shouldTick = be.progress >= 1.0f;
+            if (shouldTick) {
+                if (be instanceof UndoableAccess access) {
+                    DebugKt.debugLogger.invoke("Before piston block entity tick: " + pos.toShortString() + ", id" + access.getUndoId());
+                    UpdateMonitorHelper.INSTANCE.setRecording(UpdateMonitorHelper.INSTANCE.getUndoRecordsMap().get(access.getUndoId()));
+                }
+            }
+            PistonBlockEntity.tick(world1, pos, state1, be);
+            if (shouldTick) {
+                if (be instanceof UndoableAccess access) {
+                    DebugKt.debugLogger.invoke("After piston block entity tick: " + pos.toShortString() + ", id" + access.getUndoId());
+                    UpdateMonitorHelper.INSTANCE.setRecording(null);
+                }
             }
-            PistonBlockEntity.tick(world1, pos, state1, (PistonBlockEntity) be);
-            UpdateMonitorHelper.INSTANCE.setRecording(null);
         } : null;
     }
 }
diff --git a/src/main/java/com/github/zly2006/reden/mixin/undo/MixinSchedule.java b/src/main/java/com/github/zly2006/reden/mixin/undo/MixinSchedule.java
index 14702341..c4bace3a 100644
--- a/src/main/java/com/github/zly2006/reden/mixin/undo/MixinSchedule.java
+++ b/src/main/java/com/github/zly2006/reden/mixin/undo/MixinSchedule.java
@@ -50,6 +50,9 @@ private void afterRunSchedule(CallbackInfo ci) {
             )
     )
     private <T> void onAddSchedule(OrderedTick<T> orderedTick, CallbackInfo ci) {
+        if (orderedTick.pos().equals(new BlockPos(5, -57, -4))) {
+            System.out.println("bbbbb");
+        }
         UndoableAccess access = (UndoableAccess) orderedTick;
         PlayerData.UndoRecord recording = UpdateMonitorHelper.INSTANCE.getRecording();
         if (recording != null) {
diff --git a/src/main/java/com/github/zly2006/reden/mixinhelper/UpdateMonitorHelper.kt b/src/main/java/com/github/zly2006/reden/mixinhelper/UpdateMonitorHelper.kt
index 5bc0e3f8..589f719a 100644
--- a/src/main/java/com/github/zly2006/reden/mixinhelper/UpdateMonitorHelper.kt
+++ b/src/main/java/com/github/zly2006/reden/mixinhelper/UpdateMonitorHelper.kt
@@ -47,7 +47,7 @@ object UpdateMonitorHelper {
 
     @JvmStatic
     fun onUpdate(world: World, entry: ChainRestrictedNeighborUpdater.Entry) {
-        debugLogger("UpdateMonitorHelper.onUpdate")
+        //debugLogger("UpdateMonitorHelper.onUpdate")
         listeners.forEach { (k, v) ->
             k.invoke(world, entry)
             if (v == LifeTime.ONCE) {
@@ -58,7 +58,7 @@ object UpdateMonitorHelper {
 
     @JvmStatic
     fun onChainFinish(world: World) {
-        debugLogger("UpdateMonitorHelper.finish")
+        //debugLogger("UpdateMonitorHelper.finish")
         listeners.forEach { (k, v) ->
             if (v == LifeTime.CHAIN) {
                 listeners.remove(k)
diff --git a/src/main/resources/reden.accesswidener b/src/main/resources/reden.accesswidener
index f3da54cb..a488f19a 100644
--- a/src/main/resources/reden.accesswidener
+++ b/src/main/resources/reden.accesswidener
@@ -32,3 +32,9 @@ accessible field net/minecraft/world/chunk/Chunk heightmaps Ljava/util/Map;
 accessible field net/minecraft/command/EntitySelector PASSTHROUGH_FILTER Lnet/minecraft/util/TypeFilter;
 accessible field net/minecraft/server/integrated/IntegratedServer localPlayerUuid Ljava/util/UUID;
 accessible field net/minecraft/server/world/ServerWorld syncedBlockEventQueue Lit/unimi/dsi/fastutil/objects/ObjectLinkedOpenHashSet;
+accessible field net/minecraft/world/tick/WorldTickScheduler tickableTicks Ljava/util/Queue;
+accessible field net/minecraft/world/tick/WorldTickScheduler tickedTicks Ljava/util/List;
+accessible field net/minecraft/world/tick/WorldTickScheduler copiedTickableTicksList Ljava/util/Set;
+accessible field net/minecraft/world/tick/ChunkTickScheduler queuedTicks Ljava/util/Set;
+accessible field net/minecraft/block/entity/PistonBlockEntity progress F
+accessible field net/minecraft/block/entity/PistonBlockEntity lastProgress F