diff --git a/core/src/main/java/com/volmit/iris/engine/IrisWorldManager.java b/core/src/main/java/com/volmit/iris/engine/IrisWorldManager.java
index 9e2d50a59..3c9813fa3 100644
--- a/core/src/main/java/com/volmit/iris/engine/IrisWorldManager.java
+++ b/core/src/main/java/com/volmit/iris/engine/IrisWorldManager.java
@@ -23,6 +23,7 @@ import com.volmit.iris.core.IrisSettings;
 import com.volmit.iris.core.link.Identifier;
 import com.volmit.iris.core.loader.IrisData;
 import com.volmit.iris.core.service.ExternalDataSVC;
+import com.volmit.iris.engine.data.cache.Cache;
 import com.volmit.iris.engine.framework.Engine;
 import com.volmit.iris.engine.framework.EngineAssignedWorldManager;
 import com.volmit.iris.engine.object.*;
@@ -57,13 +58,10 @@ import org.bukkit.event.block.BlockPlaceEvent;
 import org.bukkit.event.player.PlayerTeleportEvent;
 import org.bukkit.inventory.ItemStack;
 
-import java.lang.ref.WeakReference;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.Future;
+import java.util.concurrent.*;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
@@ -81,6 +79,8 @@ public class IrisWorldManager extends EngineAssignedWorldManager {
     private final ChronoLatch cln;
     private final ChronoLatch chunkUpdater;
     private final ChronoLatch chunkDiscovery;
+    private final KMap<Long, Future<?>> cleanup = new KMap<>();
+    private final ScheduledExecutorService cleanupService;
     private double energy = 25;
     private int entityCount = 0;
     private long charge = 0;
@@ -98,6 +98,7 @@ public class IrisWorldManager extends EngineAssignedWorldManager {
         looper = null;
         chunkUpdater = null;
         chunkDiscovery = null;
+        cleanupService = null;
         id = -1;
     }
 
@@ -109,6 +110,11 @@ public class IrisWorldManager extends EngineAssignedWorldManager {
         cl = new ChronoLatch(3000);
         ecl = new ChronoLatch(250);
         clw = new ChronoLatch(1000, true);
+        cleanupService = Executors.newSingleThreadScheduledExecutor(runnable -> {
+            var thread = new Thread(runnable, "Iris Mantle Cleanup " + getTarget().getWorld().name());
+            thread.setPriority(Thread.MIN_PRIORITY);
+            return thread;
+        });
         id = engine.getCacheID();
         energy = 25;
         looper = new Looper() {
@@ -425,16 +431,14 @@ public class IrisWorldManager extends EngineAssignedWorldManager {
             return;
         }
 
-        var ref = new WeakReference<>(e.getWorld());
         int cX = e.getX(), cZ = e.getZ();
-        J.s(() -> {
-            World world = ref.get();
-            if (world == null || !world.isChunkLoaded(cX, cZ))
-                return;
+        Long key = Cache.key(e);
+        cleanup.put(key, cleanupService.schedule(() -> {
+            cleanup.remove(key);
             energy += 0.3;
             fixEnergy();
             getEngine().cleanupMantleChunk(cX, cZ);
-        }, IrisSettings.get().getPerformance().mantleCleanupDelay);
+        }, Math.max(IrisSettings.get().getPerformance().mantleCleanupDelay * 50L, 0), TimeUnit.MILLISECONDS));
 
         if (generated) {
             //INMS.get().injectBiomesFromMantle(e, getMantle());
@@ -458,6 +462,14 @@ public class IrisWorldManager extends EngineAssignedWorldManager {
         }
     }
 
+    @Override
+    public void onChunkUnload(Chunk e) {
+        final var future = cleanup.remove(Cache.key(e));
+        if (future != null) {
+            future.cancel(false);
+        }
+    }
+
     private void spawn(IrisPosition block, IrisSpawner spawner, boolean initial) {
         if (getEngine().isClosed()) {
             return;
diff --git a/core/src/main/java/com/volmit/iris/engine/framework/Engine.java b/core/src/main/java/com/volmit/iris/engine/framework/Engine.java
index 41610a722..fd972ff1d 100644
--- a/core/src/main/java/com/volmit/iris/engine/framework/Engine.java
+++ b/core/src/main/java/com/volmit/iris/engine/framework/Engine.java
@@ -1000,7 +1000,7 @@ public interface Engine extends DataProvider, Fallible, LootProvider, BlockUpdat
 
     default void cleanupMantleChunk(int x, int z) {
         if (IrisSettings.get().getPerformance().isTrimMantleInStudio() || !isStudio()) {
-            J.a(() -> getMantle().cleanupChunk(x, z));
+            getMantle().cleanupChunk(x, z);
         }
     }
 }
diff --git a/core/src/main/java/com/volmit/iris/engine/framework/EngineAssignedWorldManager.java b/core/src/main/java/com/volmit/iris/engine/framework/EngineAssignedWorldManager.java
index e53b35e5c..7dabc01de 100644
--- a/core/src/main/java/com/volmit/iris/engine/framework/EngineAssignedWorldManager.java
+++ b/core/src/main/java/com/volmit/iris/engine/framework/EngineAssignedWorldManager.java
@@ -34,6 +34,7 @@ import org.bukkit.event.block.BlockBreakEvent;
 import org.bukkit.event.block.BlockPlaceEvent;
 import org.bukkit.event.player.PlayerInteractEvent;
 import org.bukkit.event.world.ChunkLoadEvent;
+import org.bukkit.event.world.ChunkUnloadEvent;
 import org.bukkit.event.world.WorldSaveEvent;
 import org.bukkit.event.world.WorldUnloadEvent;
 import org.bukkit.inventory.EquipmentSlot;
@@ -125,6 +126,13 @@ public abstract class EngineAssignedWorldManager extends EngineAssignedComponent
         }
     }
 
+    @EventHandler
+    public void on(ChunkUnloadEvent e) {
+        if (e.getChunk().getWorld().equals(getTarget().getWorld().realWorld())) {
+            onChunkUnload(e.getChunk());
+        }
+    }
+
     @Override
     public void close() {
         super.close();
diff --git a/core/src/main/java/com/volmit/iris/engine/framework/EngineWorldManager.java b/core/src/main/java/com/volmit/iris/engine/framework/EngineWorldManager.java
index 28403d6ac..36a31b1f2 100644
--- a/core/src/main/java/com/volmit/iris/engine/framework/EngineWorldManager.java
+++ b/core/src/main/java/com/volmit/iris/engine/framework/EngineWorldManager.java
@@ -45,6 +45,8 @@ public interface EngineWorldManager {
 
     void onChunkLoad(Chunk e, boolean generated);
 
+    void onChunkUnload(Chunk e);
+
     void chargeEnergy();
 
     void teleportAsync(PlayerTeleportEvent e);