diff --git a/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitAdapter.java b/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitAdapter.java
index 4e53ff7606..dbc7de708d 100644
--- a/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitAdapter.java
+++ b/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitAdapter.java
@@ -60,8 +60,6 @@
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
 
-import java.util.Collections;
-import java.util.EnumMap;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
@@ -362,9 +360,7 @@ public static GameMode adapt(org.bukkit.GameMode gameMode) {
         return GameModes.get(gameMode.name().toLowerCase(Locale.ROOT));
     }
 
-    private static final Map<Biome, BiomeType> biomeBiomeTypeCache = Collections.synchronizedMap(
-        new EnumMap<>(Biome.class)
-    );
+    private static final Map<Biome, BiomeType> biomeBiomeTypeCache = new ConcurrentHashMap<>();
     private static final Map<BiomeType, Biome> biomeTypeBiomeCache = new ConcurrentHashMap<>();
 
     /**
@@ -408,12 +404,8 @@ public static org.bukkit.entity.EntityType adapt(EntityType entityType) {
         return Registry.ENTITY_TYPE.get(entityKey);
     }
 
-    private static final Map<Material, BlockType> materialBlockTypeCache = Collections.synchronizedMap(
-        new EnumMap<>(Material.class)
-    );
-    private static final Map<Material, ItemType> materialItemTypeCache = Collections.synchronizedMap(
-        new EnumMap<>(Material.class)
-    );
+    private static final Map<Material, BlockType> materialBlockTypeCache = new ConcurrentHashMap<>();
+    private static final Map<Material, ItemType> materialItemTypeCache = new ConcurrentHashMap<>();
 
     /**
      * Converts a Material to a BlockType.
diff --git a/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitBlockRegistry.java b/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitBlockRegistry.java
index 4407ca3d69..b6b7cece12 100644
--- a/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitBlockRegistry.java
+++ b/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitBlockRegistry.java
@@ -28,13 +28,13 @@
 import com.sk89q.worldedit.world.registry.PassthroughBlockMaterial;
 import org.bukkit.Material;
 
-import java.util.EnumMap;
+import java.util.HashMap;
 import java.util.Map;
 import java.util.OptionalInt;
 import javax.annotation.Nullable;
 
 public class BukkitBlockRegistry extends BundledBlockRegistry {
-    private final Map<Material, BukkitBlockMaterial> materialMap = new EnumMap<>(Material.class);
+    private final Map<Material, BukkitBlockMaterial> materialMap = new HashMap<>();
 
     @Override
     public Component getRichName(BlockType blockType) {