diff --git a/bukkit/src/main/java/net/william278/husksync/BukkitHuskSync.java b/bukkit/src/main/java/net/william278/husksync/BukkitHuskSync.java
index 1079bce5..9666d24c 100644
--- a/bukkit/src/main/java/net/william278/husksync/BukkitHuskSync.java
+++ b/bukkit/src/main/java/net/william278/husksync/BukkitHuskSync.java
@@ -93,9 +93,7 @@ public class BukkitHuskSync extends JavaPlugin implements HuskSync, BukkitTask.S
     private static final int METRICS_ID = 13140;
     private static final String PLATFORM_TYPE_ID = "bukkit";
 
-    private final TreeMap<Identifier, Serializer<? extends Data>> serializers = Maps.newTreeMap(
-            SerializerRegistry.DEPENDENCY_ORDER_COMPARATOR
-    );
+    private final HashMap<Identifier, Serializer<? extends Data>> serializers = Maps.newHashMap();
     private final Map<UUID, Map<Identifier, Data>> playerCustomDataStore = Maps.newConcurrentMap();
     private final Map<Integer, MapView> mapViews = Maps.newConcurrentMap();
     private final List<Migrator> availableMigrators = Lists.newArrayList();
diff --git a/common/src/main/java/net/william278/husksync/data/SerializerRegistry.java b/common/src/main/java/net/william278/husksync/data/SerializerRegistry.java
index 32e46a21..92ef321a 100644
--- a/common/src/main/java/net/william278/husksync/data/SerializerRegistry.java
+++ b/common/src/main/java/net/william278/husksync/data/SerializerRegistry.java
@@ -26,6 +26,7 @@ import org.jetbrains.annotations.NotNull;
 
 import java.util.*;
 import java.util.logging.Level;
+import java.util.stream.Collectors;
 
 public interface SerializerRegistry {
 
@@ -40,7 +41,7 @@ public interface SerializerRegistry {
      * @since 3.0
      */
     @NotNull
-    <T extends Data> TreeMap<Identifier, Serializer<T>> getSerializers();
+    <T extends Data> Map<Identifier, Serializer<T>> getSerializers();
 
     /**
      * Register a data serializer for the given {@link Identifier}
@@ -87,8 +88,7 @@ public interface SerializerRegistry {
      * @since 3.0
      */
     default Optional<Identifier> getIdentifier(@NotNull String key) {
-        return getSerializers().keySet().stream()
-                .filter(id -> id.getKey().asString().equals(key)).findFirst();
+        return getSerializers().keySet().stream().filter(e -> e.toString().equals(key)).findFirst();
     }
 
     /**
@@ -99,9 +99,7 @@ public interface SerializerRegistry {
      * @since 3.5.4
      */
     default Optional<Serializer<Data>> getSerializer(@NotNull Identifier identifier) {
-        return getSerializers().entrySet().stream()
-                .filter(entry -> entry.getKey().getKey().equals(identifier.getKey()))
-                .map(Map.Entry::getValue).findFirst();
+        return Optional.ofNullable(getSerializers().get(identifier));
     }
 
     /**
@@ -153,14 +151,14 @@ public interface SerializerRegistry {
     }
 
     /**
-     * Get the set of registered data types
+     * Get the list of registered data types, in dependency order
      *
-     * @return the set of registered data types
+     * @return the list of registered data types
      * @since 3.0
      */
     @NotNull
-    default Set<Identifier> getRegisteredDataTypes() {
-        return getSerializers().keySet();
+    default List<Identifier> getRegisteredDataTypes() {
+        return getSerializers().keySet().stream().sorted(DEPENDENCY_ORDER_COMPARATOR).toList();
     }
 
     // Returns if a data type is available and enabled in the config
diff --git a/fabric/src/main/java/net/william278/husksync/FabricHuskSync.java b/fabric/src/main/java/net/william278/husksync/FabricHuskSync.java
index 49a4de24..2e3a0082 100644
--- a/fabric/src/main/java/net/william278/husksync/FabricHuskSync.java
+++ b/fabric/src/main/java/net/william278/husksync/FabricHuskSync.java
@@ -102,9 +102,7 @@ public class FabricHuskSync implements DedicatedServerModInitializer, HuskSync,
     private static final int VERSION1_21_4 = 4189; // Current
     private static final int VERSION1_21_5 = 4323;
 
-    private final TreeMap<Identifier, Serializer<? extends Data>> serializers = Maps.newTreeMap(
-            SerializerRegistry.DEPENDENCY_ORDER_COMPARATOR
-    );
+    private final HashMap<Identifier, Serializer<? extends Data>> serializers = Maps.newHashMap();
     private final Map<UUID, Map<Identifier, Data>> playerCustomDataStore = Maps.newConcurrentMap();
     private final Map<String, Boolean> permissions = Maps.newHashMap();
     private final List<Migrator> availableMigrators = Lists.newArrayList();
diff --git a/fabric/src/main/java/net/william278/husksync/data/FabricData.java b/fabric/src/main/java/net/william278/husksync/data/FabricData.java
index ceeb2ad2..95d5eee3 100644
--- a/fabric/src/main/java/net/william278/husksync/data/FabricData.java
+++ b/fabric/src/main/java/net/william278/husksync/data/FabricData.java
@@ -49,7 +49,6 @@ import net.minecraft.stat.StatType;
 import net.minecraft.stat.Stats;
 import net.minecraft.text.Text;
 import net.minecraft.util.Identifier;
-import net.minecraft.world.GameMode;
 import net.william278.desertwell.util.ThrowingConsumer;
 import net.william278.husksync.FabricHuskSync;
 import net.william278.husksync.HuskSync;
@@ -557,13 +556,13 @@ public abstract class FabricData implements Data {
                 // This is necessary to prevent weird re-mappings with Registry#getKey()
                 //#if MC>0
                 //$$ final Registry<?> registry = stat.getValue().getRegistry();
-                //$$ final String registryId = registry.getKey().getValue().toString();
+                //$$ final String registryId = registry.getKey().getValue().value();
                 //$$ if (registryId.equals("custom_stat")) {
                 //$$    return;
                 //$$ }
                 //#else
                 final Registry<?> registry = stat.getValue().getRegistry();
-                final String registryId = registry.getKey().getValue().toString();
+                final String registryId = registry.getKey().getValue().value();
                 if (registryId.equals("custom_stat")) {
                     return;
                 }
diff --git a/fabric/src/main/java/net/william278/husksync/data/FabricUserDataHolder.java b/fabric/src/main/java/net/william278/husksync/data/FabricUserDataHolder.java
index f5fca287..7f90a403 100644
--- a/fabric/src/main/java/net/william278/husksync/data/FabricUserDataHolder.java
+++ b/fabric/src/main/java/net/william278/husksync/data/FabricUserDataHolder.java
@@ -108,8 +108,8 @@ public interface FabricUserDataHolder extends UserDataHolder {
         //#else
         final ItemStack[] combined = new ItemStack[inv.size()];
         int slot = 0;
-        while (inv.iterator().hasNext()) {
-            combined[slot] = inv.iterator().next();
+        for (ItemStack itemStack : inv) {
+            combined[slot] = itemStack;
             slot++;
         }
         return combined;