diff --git a/src/CHttpServer/CHttpServer/DuplexPipeStreamAdapter.cs b/src/CHttpServer/CHttpServer/DuplexPipeStreamAdapter.cs
index ee44f5f..6b062cb 100644
--- a/src/CHttpServer/CHttpServer/DuplexPipeStreamAdapter.cs
+++ b/src/CHttpServer/CHttpServer/DuplexPipeStreamAdapter.cs
@@ -7,7 +7,7 @@ namespace CHttpServer;
 internal class DuplexPipeStreamAdapter<TStream> : Stream, IDuplexPipe where TStream : Stream
 {
     private bool _disposed;
-    private readonly object _disposeLock = new object();
+    private readonly Lock _disposeLock = new();
 
     public DuplexPipeStreamAdapter(TStream stream, StreamPipeReaderOptions readerOptions, StreamPipeWriterOptions writerOptions)
     {
diff --git a/src/CHttpServer/CHttpServer/Http3/Http3FramingStreamWriter.cs b/src/CHttpServer/CHttpServer/Http3/Http3FramingStreamWriter.cs
index 18c0ec6..bae9dc8 100644
--- a/src/CHttpServer/CHttpServer/Http3/Http3FramingStreamWriter.cs
+++ b/src/CHttpServer/CHttpServer/Http3/Http3FramingStreamWriter.cs
@@ -154,7 +154,7 @@ public override async ValueTask<FlushResult> WriteAsync(ReadOnlyMemory<byte> sou
             _responseStream.Flush();
             return new FlushResult(isCanceled: false, isCompleted: false);
         }
-        catch (Exception ex)
+        catch (Exception)
         {
             _isCompleted = true;
             ClearSegments(CollectionsMarshal.AsSpan(_segments));
diff --git a/src/CHttpServer/CHttpServer/HttpsConnectionMiddleware.cs b/src/CHttpServer/CHttpServer/HttpsConnectionMiddleware.cs
index 928f4ac..71a4fc8 100644
--- a/src/CHttpServer/CHttpServer/HttpsConnectionMiddleware.cs
+++ b/src/CHttpServer/CHttpServer/HttpsConnectionMiddleware.cs
@@ -54,7 +54,7 @@ public async Task OnConnectionAsync(CHttp2ConnectionContext context)
         }
 
         var sslDuplexPipe = CreateSslDuplexPipe(
-            context.Transport,
+            context.Transport!,
             context.Features.Get<IMemoryPoolFeature>()?.MemoryPool ?? MemoryPool<byte>.Shared);
         var sslStream = sslDuplexPipe.Stream;
 
@@ -252,17 +252,23 @@ public X509Certificate2? ClientCertificate
     // Required for TLS Handshake feature
 
     public TlsCipherSuite? NegotiatedCipherSuite => _sslStream.NegotiatedCipherSuite;
-
+    
+    [Obsolete("Obsolete by BCL, use NegotiatedCipherSuite instead.")]
     public CipherAlgorithmType CipherAlgorithm => _sslStream.CipherAlgorithm;
 
+    [Obsolete("Obsolete by BCL, use NegotiatedCipherSuite instead.")]
     public int CipherStrength => _sslStream.CipherStrength;
 
+    [Obsolete("Obsolete by BCL, use NegotiatedCipherSuite instead.")]
     public HashAlgorithmType HashAlgorithm => _sslStream.HashAlgorithm;
 
+    [Obsolete("Obsolete by BCL, use NegotiatedCipherSuite instead.")]
     public int HashStrength => _sslStream.HashStrength;
 
+    [Obsolete("Obsolete by BCL, use NegotiatedCipherSuite instead.")]
     public ExchangeAlgorithmType KeyExchangeAlgorithm => _sslStream.KeyExchangeAlgorithm;
 
+    [Obsolete("Obsolete by BCL, use NegotiatedCipherSuite instead.")]
     public int KeyExchangeStrength => _sslStream.KeyExchangeStrength;
 
     public Task<X509Certificate2?> GetClientCertificateAsync(CancellationToken cancellationToken)
diff --git a/src/CHttpServer/TestCHttpServerApplication/Program.cs b/src/CHttpServer/TestCHttpServerApplication/Program.cs
index 3ea9cc9..8e3983a 100644
--- a/src/CHttpServer/TestCHttpServerApplication/Program.cs
+++ b/src/CHttpServer/TestCHttpServerApplication/Program.cs
@@ -58,7 +58,7 @@
 
 public class Data
 {
-    public string Message { get; set; }
+    public required string Message { get; set; }
 }
 
 [JsonSerializable(typeof(Data))]
diff --git a/tests/CHttpServer.Tests/TestBase.cs b/tests/CHttpServer.Tests/TestBase.cs
index e205e75..7d3713c 100644
--- a/tests/CHttpServer.Tests/TestBase.cs
+++ b/tests/CHttpServer.Tests/TestBase.cs
@@ -116,14 +116,17 @@ internal class TestTls : ITlsHandshakeFeature
     {
         public SslProtocols Protocol => SslProtocols.Tls12;
 
+        [Obsolete("Obsolete by BCL, use NegotiatedCipherSuite instead.")]
         public CipherAlgorithmType CipherAlgorithm => throw new NotImplementedException();
 
         public int CipherStrength => throw new NotImplementedException();
 
+        [Obsolete("Obsolete by BCL, use NegotiatedCipherSuite instead.")]
         public HashAlgorithmType HashAlgorithm => throw new NotImplementedException();
 
         public int HashStrength => throw new NotImplementedException();
 
+        [Obsolete("Obsolete by BCL, use NegotiatedCipherSuite instead.")]
         public ExchangeAlgorithmType KeyExchangeAlgorithm => throw new NotImplementedException();
 
         public int KeyExchangeStrength => throw new NotImplementedException();