diff --git a/modules/API/src/main/java/com/comphenix/protocol/PacketType.java b/modules/API/src/main/java/com/comphenix/protocol/PacketType.java
index 621037f5..772c8dde 100644
--- a/modules/API/src/main/java/com/comphenix/protocol/PacketType.java
+++ b/modules/API/src/main/java/com/comphenix/protocol/PacketType.java
@@ -4,6 +4,7 @@ import java.io.Serializable;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.UUID;
 import java.util.concurrent.Callable;
@@ -542,7 +543,7 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 		}
 
 		public String getPacketName() {
-			return WordUtils.capitalize(name().toLowerCase());
+			return WordUtils.capitalize(name().toLowerCase(Locale.ENGLISH));
 		}
 	}
 
diff --git a/modules/API/src/main/java/com/comphenix/protocol/ProtocolConfig.java b/modules/API/src/main/java/com/comphenix/protocol/ProtocolConfig.java
index 74e438d3..7710f0f9 100644
--- a/modules/API/src/main/java/com/comphenix/protocol/ProtocolConfig.java
+++ b/modules/API/src/main/java/com/comphenix/protocol/ProtocolConfig.java
@@ -20,6 +20,7 @@ import java.io.File;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 
 import org.bukkit.configuration.Configuration;
 import org.bukkit.configuration.ConfigurationSection;
@@ -464,7 +465,7 @@ public class ProtocolConfig {
 		PlayerInjectHooks hook = getDefaultMethod();
 
 		if (text != null)
-			hook = PlayerInjectHooks.valueOf(text.toUpperCase().replace(" ", "_"));
+			hook = PlayerInjectHooks.valueOf(text.toUpperCase(Locale.ENGLISH).replace(" ", "_"));
 		return hook;
 	}
 
diff --git a/modules/API/src/main/java/com/comphenix/protocol/wrappers/EnumWrappers.java b/modules/API/src/main/java/com/comphenix/protocol/wrappers/EnumWrappers.java
index 2d21fdb0..aa9eb324 100644
--- a/modules/API/src/main/java/com/comphenix/protocol/wrappers/EnumWrappers.java
+++ b/modules/API/src/main/java/com/comphenix/protocol/wrappers/EnumWrappers.java
@@ -1,6 +1,7 @@
 package com.comphenix.protocol.wrappers;
 
 import java.util.HashMap;
+import java.util.Locale;
 import java.util.Map;
 
 import org.bukkit.GameMode;
@@ -226,7 +227,7 @@ public abstract class EnumWrappers {
 			BY_NAME = new HashMap<String, Particle>();
 
 			for (Particle particle : values()) {
-				BY_NAME.put(particle.getName().toLowerCase(), particle);
+				BY_NAME.put(particle.getName().toLowerCase(Locale.ENGLISH), particle);
 				BY_ID.put(particle.getId(), particle);
 			}
 		}
@@ -264,7 +265,7 @@ public abstract class EnumWrappers {
 		}
 
 		public static Particle getByName(String name) {
-			return BY_NAME.get(name.toLowerCase());
+			return BY_NAME.get(name.toLowerCase(Locale.ENGLISH));
 		}
 
 		public static Particle getById(int id) {
@@ -302,7 +303,7 @@ public abstract class EnumWrappers {
 		}
 
 		public static SoundCategory getByKey(String key) {
-			return LOOKUP.get(key.toLowerCase());
+			return LOOKUP.get(key.toLowerCase(Locale.ENGLISH));
 		}
 	}
 
diff --git a/modules/API/src/main/java/com/comphenix/protocol/wrappers/MinecraftKey.java b/modules/API/src/main/java/com/comphenix/protocol/wrappers/MinecraftKey.java
index 10cb1362..ba4830c4 100644
--- a/modules/API/src/main/java/com/comphenix/protocol/wrappers/MinecraftKey.java
+++ b/modules/API/src/main/java/com/comphenix/protocol/wrappers/MinecraftKey.java
@@ -17,6 +17,7 @@
 package com.comphenix.protocol.wrappers;
 
 import java.lang.reflect.Constructor;
+import java.util.Locale;
 
 import com.comphenix.protocol.reflect.EquivalentConverter;
 import com.comphenix.protocol.reflect.StructureModifier;
@@ -70,7 +71,7 @@ public class MinecraftKey {
 	 * @return The resulting key
 	 */
 	public static MinecraftKey fromEnum(Enum<?> value) {
-		return new MinecraftKey(value.name().toLowerCase().replace("_", "."));
+		return new MinecraftKey(value.name().toLowerCase(Locale.ENGLISH).replace("_", "."));
 	}
 
 	/**
@@ -104,7 +105,7 @@ public class MinecraftKey {
 	 * @return The enum format
 	 */
 	public String getEnumFormat() {
-		return key.toUpperCase().replace(".", "_");
+		return key.toUpperCase(Locale.ENGLISH).replace(".", "_");
 	}
 
 	private static Constructor<?> constructor = null;
diff --git a/modules/ProtocolLib/src/main/java/com/comphenix/protocol/PacketTypeParser.java b/modules/ProtocolLib/src/main/java/com/comphenix/protocol/PacketTypeParser.java
index ab95a398..947616ed 100644
--- a/modules/ProtocolLib/src/main/java/com/comphenix/protocol/PacketTypeParser.java
+++ b/modules/ProtocolLib/src/main/java/com/comphenix/protocol/PacketTypeParser.java
@@ -4,6 +4,7 @@ import java.util.Collection;
 import java.util.Deque;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Locale;
 import java.util.Set;
 
 import com.comphenix.protocol.PacketType.Protocol;
@@ -53,7 +54,7 @@ class PacketTypeParser {
 		// And finally, parse packet names if we have a protocol
 		if (protocol != null) {
 			for (Iterator<String> it = arguments.iterator(); it.hasNext(); ) {
-				String name = it.next().toUpperCase();
+				String name = it.next().toUpperCase(Locale.ENGLISH);
 				Collection<PacketType> names = PacketType.fromName(name);
 				
 				for (PacketType type : names) {