diff --git a/TanksServer/Endpoints.cs b/TanksServer/Endpoints.cs
index f139715..a98c351 100644
--- a/TanksServer/Endpoints.cs
+++ b/TanksServer/Endpoints.cs
@@ -24,7 +24,10 @@ internal static class Endpoints
             if (name.Length > 12)
                 return Results.BadRequest("name too long");
 
-            var player = playerService.GetOrAdd(name, id ?? Guid.NewGuid());
+            if (!id.HasValue || id.Value == Guid.Empty)
+                id = Guid.NewGuid();
+
+            var player = playerService.GetOrAdd(name, id.Value);
             return player != null
                 ? Results.Ok(new NameId(player.Name, player.Id))
                 : Results.Unauthorized();
diff --git a/tank-frontend/src/App.tsx b/tank-frontend/src/App.tsx
index e065fc7..52631e6 100644
--- a/tank-frontend/src/App.tsx
+++ b/tank-frontend/src/App.tsx
@@ -11,9 +11,10 @@ import Scoreboard from "./Scoreboard.tsx";
 import Button from "./components/Button.tsx";
 import './App.css';
 import {getRandomTheme, useStoredTheme} from "./theme.ts";
+import {EmptyGuid} from "./Guid.ts";
 
 const getNewNameId = () => ({
-    id: crypto.randomUUID(),
+    id: EmptyGuid,
     name: ''
 });