diff --git a/src/com/massivecraft/mcore/ConfServer.java b/src/com/massivecraft/mcore/ConfServer.java
index a3056119..fe8299d5 100644
--- a/src/com/massivecraft/mcore/ConfServer.java
+++ b/src/com/massivecraft/mcore/ConfServer.java
@@ -32,6 +32,7 @@ public class ConfServer extends SimpleConfig
 	public static String dburi = "default";
 	
 	public static boolean usingPlayerConnectionWrap = true;
+	public static boolean forceOnePlayerNameCase = true;
 	
 	public static List<String> aliasesOuterMCore = MUtil.list("mcore");
 	public static List<String> aliasesOuterMCoreUsys = MUtil.list("usys");
diff --git a/src/com/massivecraft/mcore/InternalListener.java b/src/com/massivecraft/mcore/InternalListener.java
index 11dd1ce0..beee2edc 100644
--- a/src/com/massivecraft/mcore/InternalListener.java
+++ b/src/com/massivecraft/mcore/InternalListener.java
@@ -31,8 +31,10 @@ import com.massivecraft.mcore.event.MCoreSenderUnregisterEvent;
 import com.massivecraft.mcore.mixin.Mixin;
 import com.massivecraft.mcore.store.Coll;
 import com.massivecraft.mcore.store.SenderColl;
+import com.massivecraft.mcore.util.MUtil;
 import com.massivecraft.mcore.util.SenderUtil;
 import com.massivecraft.mcore.util.SmokeUtil;
+import com.massivecraft.mcore.util.Txt;
 import com.massivecraft.mcore.wrap.PlayerConnectionWrapMCore;
 
 public class InternalListener implements Listener
@@ -54,6 +56,44 @@ public class InternalListener implements Listener
 		Bukkit.getPluginManager().registerEvents(this, MCore.get());
 	}
 	
+	// -------------------------------------------- //
+	// FORCE ONE PLAYER NAME CASE
+	// -------------------------------------------- //
+	// This is used with offline servers to prevent bugs on case sensitive file systems.
+	
+	@EventHandler(priority = EventPriority.LOWEST)
+	public void forceOnePlayerNameCase(PlayerLoginEvent event)
+	{
+		// If we are enforcing one player name case ...
+		if (!ConfServer.forceOnePlayerNameCase) return;
+		
+		// ... and the server is running in offline mode ...
+		if (Bukkit.getOnlineMode()) return;
+		
+		// ... prepare vars ...
+		Player player = event.getPlayer();
+		String playerName = player.getName();
+		
+		// ... is the player already online? ...
+		for (Player onlinePlayer: Bukkit.getOnlinePlayers())
+		{
+			if (!playerName.equalsIgnoreCase(onlinePlayer.getName())) continue;
+			event.setResult(Result.KICK_OTHER);
+			event.setKickMessage(Txt.parse("<b>The player <h>%s <b>is already online.", onlinePlayer.getName()));
+			return;
+		}
+		
+		// ... is the first found file name different?
+		for (String pdname : MUtil.getPlayerDirectoryNames())
+		{
+			if (!playerName.equalsIgnoreCase(pdname)) continue;
+			if (playerName.equals(pdname)) break;
+			event.setResult(Result.KICK_OTHER);
+			event.setKickMessage(Txt.parse("<b>Invalid uppercase and lowercase letters in name.\n<i>Please spell this name like \"<h>%s<i>\".", pdname));
+		}
+		
+	}
+	
 	// -------------------------------------------- //
 	// PLAYER CONNECTION WRAP INJECTION
 	// -------------------------------------------- //