diff --git a/src/main/java/net/minestom/server/instance/block/BlockImpl.java b/src/main/java/net/minestom/server/instance/block/BlockImpl.java
index c3bbe0874..b20525b02 100644
--- a/src/main/java/net/minestom/server/instance/block/BlockImpl.java
+++ b/src/main/java/net/minestom/server/instance/block/BlockImpl.java
@@ -3,7 +3,7 @@ package net.minestom.server.instance.block;
 import com.github.benmanes.caffeine.cache.Cache;
 import com.github.benmanes.caffeine.cache.Caffeine;
 import com.google.gson.JsonObject;
-import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 import net.minestom.server.registry.Registry;
 import net.minestom.server.tag.Tag;
 import net.minestom.server.utils.block.BlockUtils;
@@ -17,7 +17,7 @@ import java.util.function.Function;
 
 final class BlockImpl implements Block {
     // Block state -> block object
-    private static final Int2ObjectOpenHashMap<Block> BLOCK_STATE_MAP = new Int2ObjectOpenHashMap<>();
+    private static final ObjectArrayList<Block> BLOCK_STATE_MAP = new ObjectArrayList<>();
     private static final Registry.Container<Block> CONTAINER = new Registry.Container<>(Registry.Resource.BLOCKS,
             (container, namespace, object) -> {
                 final JsonObject stateObject = object.remove("states").getAsJsonObject();
@@ -30,7 +30,7 @@ final class BlockImpl implements Block {
                     final var propertyMap = BlockUtils.parseProperties(query);
                     final Block block = new BlockImpl(Registry.block(namespace, object, stateOverride),
                             unmodifiableEntries, propertyMap, null, null);
-                    BLOCK_STATE_MAP.put(block.stateId(), block);
+                    BLOCK_STATE_MAP.add(block.stateId(), block);
                     propertyEntry.put(propertyMap, block);
                 }
                 // Register default state
diff --git a/src/main/java/net/minestom/server/registry/Registry.java b/src/main/java/net/minestom/server/registry/Registry.java
index bf66d2782..795d909c6 100644
--- a/src/main/java/net/minestom/server/registry/Registry.java
+++ b/src/main/java/net/minestom/server/registry/Registry.java
@@ -4,7 +4,7 @@ import com.google.gson.Gson;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.gson.stream.JsonReader;
-import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 import net.minestom.server.entity.EntitySpawnType;
 import net.minestom.server.entity.EquipmentSlot;
 import net.minestom.server.instance.block.Block;
@@ -76,7 +76,7 @@ public final class Registry {
         // namespace -> registry data
         private final Map<String, T> namespaceMap = new HashMap<>();
         // id -> registry data
-        private final Int2ObjectOpenHashMap<T> idMap = new Int2ObjectOpenHashMap<>();
+        private final ObjectArrayList<T> idMap = new ObjectArrayList<>();
         private final Collection<T> objects = Collections.unmodifiableCollection(namespaceMap.values());
 
         private final boolean initialized;
@@ -111,7 +111,7 @@ public final class Registry {
 
         public void register(@NotNull T value) {
             Check.stateCondition(initialized, "Registering is only available within the loader lambda.");
-            this.idMap.put(value.id(), value);
+            this.idMap.add(value.id(), value);
             this.namespaceMap.put(value.name(), value);
         }