diff --git a/shiroha-server/src/main/java/io/nanachiyo0721/shiroha/utils/ReferenceCountingChunkLoader.java b/shiroha-server/src/main/java/io/nanachiyo0721/shiroha/utils/ReferenceCountingChunkLoader.java
index 2781f3a..8a40337 100644
--- a/shiroha-server/src/main/java/io/nanachiyo0721/shiroha/utils/ReferenceCountingChunkLoader.java
+++ b/shiroha-server/src/main/java/io/nanachiyo0721/shiroha/utils/ReferenceCountingChunkLoader.java
@@ -218,34 +218,45 @@ public class ReferenceCountingChunkLoader {
 
         final ReferenceCountData[] toRemoveTicket = new ReferenceCountData[1];
 
-        for (ConcurrentChainedLong2ReferenceHashTable.TableEntry<ReferenceCountData> counterEntry : this.referenceCounters.entrySet()) {
-            final long coord = counterEntry.getKey();
-            final ReferenceCountData counterData = counterEntry.getValue();
+        final it.unimi.dsi.fastutil.longs.LongIterator sectionsIterator = currentRegion.getOwnedSectionsUnsynchronised();
+        while (sectionsIterator.hasNext()) {
+            final long sectionKey = sectionsIterator.nextLong();
+            final int sectionX = CoordinateUtils.getChunkX(sectionKey);
+            final int sectionZ = CoordinateUtils.getChunkZ(sectionKey);
 
-            if (currentRegion == this.world.regioniser.getRegionAtUnsynchronised(CoordinateUtils.getChunkX(coord), CoordinateUtils.getChunkZ(coord))) {
-                long curr = counterData.referenceTTL.get();
-                if (curr == (curr = counterData.referenceTTL.compareAndExchange(curr, curr - 1))) {
-                    if (counterData.referenceCount.get() != 0L) {
-                        counterData.referenceTTL.set(MAX_CHUNK_TTL_TICKS);
-                        continue;
-                    }
+            final int chunkX = sectionX << this.world.regioniser.sectionChunkShift;
+            final int chunkZ = sectionZ << this.world.regioniser.sectionChunkShift;
+            final long coord = CoordinateUtils.getChunkKey(chunkX, chunkZ);
+            final ReferenceCountData counterData = this.referenceCounters.get(coord);
 
-                    if (curr <= 0) {
-                        this.referenceCounters.computeIfPresent(coord, (final long keyInMap, final ReferenceCountData valueInMap) -> {
-                            if (valueInMap.referenceCount.get() != 0L) {
-                                valueInMap.referenceTTL.set(MAX_CHUNK_TTL_TICKS);
-                                return valueInMap;
-                            }
+            // removed
+            if (counterData == null) {
+                continue;
+            }
 
-                            toRemoveTicket[0] = valueInMap;
+            // do ttl
+            long curr = counterData.referenceTTL.get();
+            if (curr == (curr = counterData.referenceTTL.compareAndExchange(curr, curr - 1))) {
+                if (counterData.referenceCount.get() != 0L) {
+                    counterData.referenceTTL.set(MAX_CHUNK_TTL_TICKS);
+                    continue;
+                }
 
-                            return null;
-                        });
-
-                        if (toRemoveTicket[0] != null) {
-                            this.removeTicket(coord, toRemoveTicket[0].id);
-                            toRemoveTicket[0] = null;
+                if (curr <= 0) {
+                    this.referenceCounters.computeIfPresent(coord, (final long keyInMap, final ReferenceCountData valueInMap) -> {
+                        if (valueInMap.referenceCount.get() != 0L) {
+                            valueInMap.referenceTTL.set(MAX_CHUNK_TTL_TICKS);
+                            return valueInMap;
                         }
+
+                        toRemoveTicket[0] = valueInMap;
+
+                        return null;
+                    });
+
+                    if (toRemoveTicket[0] != null) {
+                        this.removeTicket(coord, toRemoveTicket[0].id);
+                        toRemoveTicket[0] = null;
                     }
                 }
             }