diff --git a/MCGalaxy/Commands/Overseer.cs b/MCGalaxy/Commands/Overseer.cs
index 7b145747e..84309cf28 100644
--- a/MCGalaxy/Commands/Overseer.cs
+++ b/MCGalaxy/Commands/Overseer.cs
@@ -443,6 +443,9 @@ namespace MCGalaxy.Commands.World {
             "&H  With <name>, renames to 'yourname[name]'.",
         };
         static void HandleRename(Player p, string args) {
+            if (args.Length > 0 && !Formatter.IsValidName(p, args, "os name", Player.USERNAME_ALPHABET)) {
+                return;
+            }
             UseCommand(p, "RenameLvl", p.level.name + " " + GetLevelName(p, args));
         }
         
diff --git a/MCGalaxy/util/Formatting/Formatter.cs b/MCGalaxy/util/Formatting/Formatter.cs
index 21311f98f..015650eaf 100644
--- a/MCGalaxy/util/Formatting/Formatter.cs
+++ b/MCGalaxy/util/Formatting/Formatter.cs
@@ -90,7 +90,7 @@ namespace MCGalaxy
             return IsValidName(p, name, "player", alphabet);
         }
         
-        static bool IsValidName(Player p, string name, string type, string alphabet) {
+        public static bool IsValidName(Player p, string name, string type, string alphabet) {
             if (name.Length > 0 && name.ContainsAllIn(alphabet)) return true;
             p.Message("\"{0}\" is not a valid {1} name.", name, type);
             return false;