diff --git a/AMNet.Server/CardPresenter.cs b/AMNet.Server/CardPresenter.cs
index 5221c55..2d053a4 100644
--- a/AMNet.Server/CardPresenter.cs
+++ b/AMNet.Server/CardPresenter.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Globalization;
 using System.Linq;
+using System.Threading;
 
 namespace AMNet.Server;
 
@@ -9,9 +10,9 @@ namespace AMNet.Server;
 /// </summary>
 internal class CardPresenter
 {
-    private readonly object _cardLock = new();
+    private readonly Lock _cardLock = new();
     private StoredCard _currentCard;
-    
+
     public record StoredCard(byte[] Value, string OriginalValue, long ExpiresAt)
     {
         public bool Expired => Environment.TickCount64 >= ExpiresAt;
@@ -65,7 +66,7 @@ internal class CardPresenter
                 return null;
             }
         }
-        
+
         var card = new StoredCard(bytes, matrixCode, Environment.TickCount64 + validFor);
 
         lock (_cardLock)
diff --git a/AMNet.Server/Config.cs b/AMNet.Server/Config.cs
index 260df44..954fd87 100644
--- a/AMNet.Server/Config.cs
+++ b/AMNet.Server/Config.cs
@@ -14,17 +14,17 @@ internal static class Config
     {
         GameId = ReadKey(IOSection, "gameId", 4);
         ServerName = ReadKey(IOSection, "serverName", 26, Environment.MachineName);
-        
+
         EnableAimeTxt = PInvoke.GetPrivateProfileInt(IOSection, "enableKeyboardMode", 1, ConfigFileName) > 0;
         AimeTxtPath = ReadKey("aime", "aimePath", PInvoke.MAX_PATH, @"DEVICE\aime.txt");
     }
-    
+
     public static string GameId { get; }
     public static string ServerName { get; }
-    
+
     public static bool EnableAimeTxt { get; }
     public static string AimeTxtPath { get; }
-    
+
     internal static unsafe string ReadKey(string section, string key, uint maxLength, string @default = null)
     {
         // +1 for null terminator
diff --git a/AMNet.Server/WebServer.cs b/AMNet.Server/WebServer.cs
index 21917cb..e238f5b 100644
--- a/AMNet.Server/WebServer.cs
+++ b/AMNet.Server/WebServer.cs
@@ -63,7 +63,7 @@ internal static partial class WebServer
         builder.Services.AddSingleton<CardPresenter>();
 
         var app = builder.Build();
-        
+
         app.UseCors();
 
         app.MapGet("/amnet/info", ServerInfo);
@@ -83,7 +83,7 @@ internal static partial class WebServer
             Config.ServerName,
             Environment.TickCount64 - startedAt,
             lastPollAt < 0 ? null : Environment.TickCount64 - lastPollAt);
-        
+
         return Results.Ok(state);
     }