1 files changed, 5 insertions, 4 deletions
diff --git a/Jellyfin.Api/Controllers/StartupController.cs b/Jellyfin.Api/Controllers/StartupController.cs
index 09f20558f..3bb68553d 100644
--- a/Jellyfin.Api/Controllers/StartupController.cs
+++ b/Jellyfin.Api/Controllers/StartupController.cs
@@ -1,3 +1,4 @@
+using System;
 using System.ComponentModel.DataAnnotations;
 using System.Linq;
 using System.Threading.Tasks;
@@ -131,16 +132,16 @@ public class StartupController : BaseJellyfinApiController
     [ProducesResponseType(StatusCodes.Status204NoContent)]
     public async Task<ActionResult> UpdateStartupUser([FromBody] StartupUserDto startupUserDto)
     {
+        ArgumentNullException.ThrowIfNull(startupUserDto.Name);
+        _userManager.ThrowIfInvalidUsername(startupUserDto.Name);
+
         var user = _userManager.Users.First();
         if (string.IsNullOrWhiteSpace(startupUserDto.Password))
         {
             return BadRequest("Password must not be empty");
         }
 
-        if (startupUserDto.Name is not null)
-        {
-            user.Username = startupUserDto.Name;
-        }
+        user.Username = startupUserDto.Name;
 
         await _userManager.UpdateUserAsync(user).ConfigureAwait(false);