diff --git a/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/WorldEditPlugin.java b/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/WorldEditPlugin.java
index 15b79a4d9..ee7bf48cf 100644
--- a/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/WorldEditPlugin.java
+++ b/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/WorldEditPlugin.java
@@ -140,8 +140,8 @@ public class WorldEditPlugin extends JavaPlugin { //implements TabCompleter
 
     private void init() {
         if (lookupNames != null) {
-            lookupNames.putIfAbsent("FastAsyncWorldEdit".toLowerCase(Locale.ENGLISH), this);
-            lookupNames.putIfAbsent("WorldEdit".toLowerCase(Locale.ENGLISH), this);
+            lookupNames.putIfAbsent("FastAsyncWorldEdit".toLowerCase(Locale.ROOT), this);
+            lookupNames.putIfAbsent("WorldEdit".toLowerCase(Locale.ROOT), this);
             lookupNames.putIfAbsent("FastAsyncWorldEdit", this);
             lookupNames.putIfAbsent("WorldEdit", this);
             rename();
@@ -246,7 +246,7 @@ public class WorldEditPlugin extends JavaPlugin { //implements TabCompleter
         for (org.bukkit.entity.EntityType entityType : org.bukkit.entity.EntityType.values()) {
             String mcid = entityType.getName();
             if (mcid != null) {
-                EntityType.REGISTRY.register("minecraft:" + mcid.toLowerCase(), new EntityType("minecraft:" + mcid.toLowerCase()));
+                EntityType.REGISTRY.register("minecraft:" + mcid.toLowerCase(Locale.ROOT), new EntityType("minecraft:" + mcid.toLowerCase(Locale.ROOT)));
             }
         }
     }
diff --git a/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/adapter/IBukkitAdapter.java b/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/adapter/IBukkitAdapter.java
index b3e7adc07..6ae11c23a 100644
--- a/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/adapter/IBukkitAdapter.java
+++ b/worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/adapter/IBukkitAdapter.java
@@ -26,6 +26,8 @@ import org.bukkit.block.data.BlockData;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
 
+import java.util.Locale;
+
 import static com.google.common.base.Preconditions.checkNotNull;
 
 public interface IBukkitAdapter {
@@ -231,7 +233,7 @@ public interface IBukkitAdapter {
      */
     default GameMode adapt(org.bukkit.GameMode gameMode) {
         checkNotNull(gameMode);
-        return GameModes.get(gameMode.name().toLowerCase());
+        return GameModes.get(gameMode.name().toLowerCase(Locale.ROOT));
     }
 
     /**
@@ -241,14 +243,14 @@ public interface IBukkitAdapter {
      * @return WorldEdit EntityType
      */
     default EntityType adapt(org.bukkit.entity.EntityType entityType) {
-        return EntityTypes.get(entityType.getName().toLowerCase());
+        return EntityTypes.get(entityType.getName().toLowerCase(Locale.ROOT));
     }
 
     default org.bukkit.entity.EntityType adapt(EntityType entityType) {
         if (!entityType.getId().startsWith("minecraft:")) {
             throw new IllegalArgumentException("Bukkit only supports vanilla entities");
         }
-        return org.bukkit.entity.EntityType.fromName(entityType.getId().substring(10).toLowerCase());
+        return org.bukkit.entity.EntityType.fromName(entityType.getId().substring(10).toLowerCase(Locale.ROOT));
     }
 
     /**
@@ -371,6 +373,6 @@ public interface IBukkitAdapter {
     }
 
     default BiomeType adapt(Biome biome) {
-        return BiomeTypes.get(biome.name().toLowerCase());
+        return BiomeTypes.get(biome.name().toLowerCase(Locale.ROOT));
     }
 }
diff --git a/worldedit-core/src/main/java/com/boydti/fawe/util/IncendoPaster.java b/worldedit-core/src/main/java/com/boydti/fawe/util/IncendoPaster.java
index 86a415298..7c9128453 100644
--- a/worldedit-core/src/main/java/com/boydti/fawe/util/IncendoPaster.java
+++ b/worldedit-core/src/main/java/com/boydti/fawe/util/IncendoPaster.java
@@ -43,7 +43,7 @@ public final class IncendoPaster {
         if (pasteApplication == null || pasteApplication.isEmpty()) {
             throw new IllegalArgumentException("paste application cannot be null, nor empty");
         }
-        if (!VALID_APPLICATIONS.contains(pasteApplication.toLowerCase(Locale.ENGLISH))) {
+        if (!VALID_APPLICATIONS.contains(pasteApplication.toLowerCase(Locale.ROOT))) {
             throw new IllegalArgumentException(
                 String.format("Unknown application name: %s", pasteApplication));
         }
diff --git a/worldedit-core/src/main/java/com/sk89q/worldedit/extent/clipboard/io/ClipboardFormats.java b/worldedit-core/src/main/java/com/sk89q/worldedit/extent/clipboard/io/ClipboardFormats.java
index 375f4c2dc..f37245d6c 100644
--- a/worldedit-core/src/main/java/com/sk89q/worldedit/extent/clipboard/io/ClipboardFormats.java
+++ b/worldedit-core/src/main/java/com/sk89q/worldedit/extent/clipboard/io/ClipboardFormats.java
@@ -72,7 +72,7 @@ public class ClipboardFormats {
         checkNotNull(format);
 
         for (String key : format.getAliases()) {
-            String lowKey = key.toLowerCase(Locale.ENGLISH);
+            String lowKey = key.toLowerCase(Locale.ROOT);
             ClipboardFormat old = aliasMap.put(lowKey, format);
             if (old != null) {
                 aliasMap.put(lowKey, old);
@@ -80,7 +80,7 @@ public class ClipboardFormats {
             }
         }
         for (String ext : format.getFileExtensions()) {
-            String lowExt = ext.toLowerCase(Locale.ENGLISH);
+            String lowExt = ext.toLowerCase(Locale.ROOT);
             fileExtensionMap.put(lowExt, format);
         }
         registeredFormats.add(format);
@@ -102,7 +102,7 @@ public class ClipboardFormats {
     @Nullable
     public static ClipboardFormat findByAlias(String alias) {
         checkNotNull(alias);
-        return aliasMap.get(alias.toLowerCase(Locale.ENGLISH).trim());
+        return aliasMap.get(alias.toLowerCase(Locale.ROOT).trim());
     }
 
     /**
diff --git a/worldedit-core/src/main/java/com/sk89q/worldedit/util/paste/IncendoPaste.java b/worldedit-core/src/main/java/com/sk89q/worldedit/util/paste/IncendoPaste.java
index 38c460764..7dd004b66 100644
--- a/worldedit-core/src/main/java/com/sk89q/worldedit/util/paste/IncendoPaste.java
+++ b/worldedit-core/src/main/java/com/sk89q/worldedit/util/paste/IncendoPaste.java
@@ -45,7 +45,7 @@ public final class IncendoPaste implements Paster{
         if (pasteApplication == null || pasteApplication.isEmpty()) {
             throw new IllegalArgumentException("paste application cannot be null, nor empty");
         }
-        if (!VALID_APPLICATIONS.contains(pasteApplication.toLowerCase(Locale.ENGLISH))) {
+        if (!VALID_APPLICATIONS.contains(pasteApplication.toLowerCase(Locale.ROOT))) {
             throw new IllegalArgumentException(
                 String.format("Unknown application name: %s", pasteApplication));
         }
diff --git a/worldedit-core/src/main/java/com/sk89q/worldedit/world/block/BlockTypes.java b/worldedit-core/src/main/java/com/sk89q/worldedit/world/block/BlockTypes.java
index dcf1baba6..9a7bf8323 100644
--- a/worldedit-core/src/main/java/com/sk89q/worldedit/world/block/BlockTypes.java
+++ b/worldedit-core/src/main/java/com/sk89q/worldedit/world/block/BlockTypes.java
@@ -41,6 +41,7 @@ import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
@@ -812,7 +813,7 @@ public final class BlockTypes {
             for (Field field : oldFields) {
                 if (field.getType() == int.class) {
                     int internalId = field.getInt(null);
-                    String id = "minecraft:" + field.getName().toLowerCase();
+                    String id = "minecraft:" + field.getName().toLowerCase(Locale.ROOT);
                     String defaultState = blockMap.remove(id);
                     if (defaultState == null) {
                         if (internalId != 0) {
@@ -844,7 +845,7 @@ public final class BlockTypes {
 
             // Add to $Registry
             for (BlockType type : values) {
-                $REGISTRY.put(type.getId().toLowerCase(), type);
+                $REGISTRY.put(type.getId().toLowerCase(Locale.ROOT), type);
             }
             states = stateList.toArray(new BlockState[stateList.size()]);
 
@@ -888,7 +889,7 @@ public final class BlockTypes {
      */
 
     public static BlockType parse(final String type) throws InputParseException {
-        final String inputLower = type.toLowerCase();
+        final String inputLower = type.toLowerCase(Locale.ROOT);
         String input = inputLower;
 
         if (!input.split("\\[", 2)[0].contains(":")) input = "minecraft:" + input;