diff --git a/app/src/app.service.ts b/app/src/app.service.ts
index 257720f..955b5f6 100644
--- a/app/src/app.service.ts
+++ b/app/src/app.service.ts
@@ -16,7 +16,10 @@ import {
   JoinLobbyEvent,
 } from 'interface';
 import { createWsExceptionFilter } from './websocket-exception-filter';
-import { PlayerNotFoundException } from './exceptions';
+import {
+  MissingPlayerNameException,
+  PlayerNotFoundException,
+} from './exceptions';
 
 @WebSocketGateway({ cors: true })
 @Injectable()
@@ -31,7 +34,12 @@ export class AppService implements OnGatewayConnection {
     this.playerService.createPlayer(client.id);
   }
 
-  @UseFilters(createWsExceptionFilter([PlayerNotFoundException]))
+  @UseFilters(
+    createWsExceptionFilter([
+      PlayerNotFoundException,
+      MissingPlayerNameException,
+    ]),
+  )
   @SubscribeMessage(ClientEvent.CREATE_LOBBY)
   handleCreateLobby(
     @ConnectedSocket() client: Socket,
@@ -47,6 +55,12 @@ export class AppService implements OnGatewayConnection {
     });
   }
 
+  @UseFilters(
+    createWsExceptionFilter([
+      PlayerNotFoundException,
+      MissingPlayerNameException,
+    ]),
+  )
   @SubscribeMessage(ClientEvent.JOIN_LOBBY)
   handleJoinLobby(
     @ConnectedSocket() client: Socket,
diff --git a/app/src/exceptions.ts b/app/src/exceptions.ts
index e845efd..886ad1b 100644
--- a/app/src/exceptions.ts
+++ b/app/src/exceptions.ts
@@ -10,6 +10,12 @@ export abstract class WebSocketException extends WsException {
   }
 }
 
+export class MissingPlayerNameException extends WebSocketException {
+  constructor() {
+    super('Missing player name', ErrorCode.MISSING_USER_NAME);
+  }
+}
+
 export class PlayerNotFoundException extends WebSocketException {
   constructor(playerId: string) {
     super(
diff --git a/app/src/players/player.service.ts b/app/src/players/player.service.ts
index db45efe..adc7cc8 100644
--- a/app/src/players/player.service.ts
+++ b/app/src/players/player.service.ts
@@ -1,6 +1,9 @@
 import { Injectable, Logger } from '@nestjs/common';
 import { Player } from './player';
-import { PlayerNotFoundException } from 'src/exceptions';
+import {
+  MissingPlayerNameException,
+  PlayerNotFoundException,
+} from 'src/exceptions';
 
 @Injectable()
 export class PlayerService {
@@ -13,6 +16,9 @@ export class PlayerService {
   }
 
   addUserName(socketId: string, userName: string) {
+    if (!userName) {
+      throw new MissingPlayerNameException();
+    }
     this.players.get(socketId).userName = userName;
   }
 
diff --git a/interface/server-events/CreateLobbyError.ts b/interface/server-events/CreateLobbyError.ts
index d488e52..8003490 100644
--- a/interface/server-events/CreateLobbyError.ts
+++ b/interface/server-events/CreateLobbyError.ts
@@ -3,7 +3,7 @@ import { Socket as ClientSocket } from "socket.io-client";
 import { ErrorCode, ServerError } from "./ServerError";
 
 export type CreateLobbyError = {
-  error: ErrorCode.PLAYER_NOT_FOUND | ErrorCode.GAME_NOT_FOUND;
+  error: ErrorCode;
 };
 
 export const emitCreateLobbyError = (
diff --git a/interface/server-events/ServerError.ts b/interface/server-events/ServerError.ts
index adb14fd..8ba99a3 100644
--- a/interface/server-events/ServerError.ts
+++ b/interface/server-events/ServerError.ts
@@ -6,4 +6,5 @@ export enum ServerError {
 export enum ErrorCode {
   PLAYER_NOT_FOUND = "player-not-found",
   GAME_NOT_FOUND = "game-not-found",
+  MISSING_USER_NAME = "player-user-name-not-found",
 }