diff --git a/Benchmarking/Benchmark/Benchmark.csproj b/Benchmarking/Benchmark/Benchmark.csproj
index 43c2aab..f9f1474 100644
--- a/Benchmarking/Benchmark/Benchmark.csproj
+++ b/Benchmarking/Benchmark/Benchmark.csproj
@@ -7,8 +7,8 @@
 
   <ItemGroup>
     <PackageReference Include="BenchmarkDotNet" Version="0.12.0" />
-    <PackageReference Include="Capnp.Net.Runtime" Version="1.3.93-g73bd1de241" />
-    <PackageReference Include="CapnpC.CSharp.MsBuild.Generation" Version="1.2.138" />
+    <PackageReference Include="Capnp.Net.Runtime" Version="1.3.94-g87575f12bf" />
+    <PackageReference Include="CapnpC.CSharp.MsBuild.Generation" Version="1.3.94-g87575f12bf" />
     <PackageReference Include="Google.Protobuf" Version="3.11.3" />
     <PackageReference Include="Grpc.Net.Client" Version="2.27.0" />
     <PackageReference Include="Grpc.Tools" Version="2.27.0">
diff --git a/Benchmarking/EchoServiceCapnp/EchoServiceCapnp.csproj b/Benchmarking/EchoServiceCapnp/EchoServiceCapnp.csproj
index 3b41a29..5954408 100644
--- a/Benchmarking/EchoServiceCapnp/EchoServiceCapnp.csproj
+++ b/Benchmarking/EchoServiceCapnp/EchoServiceCapnp.csproj
@@ -6,7 +6,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Capnp.Net.Runtime" Version="1.3.93-g73bd1de241" />
+    <PackageReference Include="Capnp.Net.Runtime" Version="1.3.94-g87575f12bf" />
     <PackageReference Include="CapnpC.CSharp.MsBuild.Generation" Version="1.3.92-gdb2d6bce2e" />
   </ItemGroup>
 
diff --git a/Capnp.Net.Runtime/Util/AsyncNetworkStreamAdapter.cs b/Capnp.Net.Runtime/Util/AsyncNetworkStreamAdapter.cs
index cfd255a..9c9481e 100644
--- a/Capnp.Net.Runtime/Util/AsyncNetworkStreamAdapter.cs
+++ b/Capnp.Net.Runtime/Util/AsyncNetworkStreamAdapter.cs
@@ -7,15 +7,24 @@ namespace Capnp.Util
 {
     internal class AsyncNetworkStreamAdapter : Stream
     {
-        readonly NetworkStream _stream;
-        readonly object _reentrancyBlocker = new object();
-        //Exception? _bufferedException;
+        // Async I/O pays off for large payloads. Perf. profiling gave a threshold around 200kB
+        const int DefaultAsyncThreshold = 200000;
 
-        public AsyncNetworkStreamAdapter(Stream stream)
+        readonly NetworkStream _stream;
+        readonly int _asyncThreshold;
+        readonly object _reentrancyBlocker = new object();
+        Exception? _bufferedException;
+
+        public AsyncNetworkStreamAdapter(Stream stream, int asyncThreshold)
         {
+            _asyncThreshold = asyncThreshold;
             _stream = stream as NetworkStream ?? throw new ArgumentException("stream argument must be a NetworkStream");
         }
 
+        public AsyncNetworkStreamAdapter(Stream stream): this(stream, DefaultAsyncThreshold)
+        {
+        }
+
         public override bool CanRead => true;
 
         public override bool CanSeek => false;
@@ -32,7 +41,8 @@ namespace Capnp.Util
 
         public override void Flush()
         {
-            _stream.Flush();
+            _stream.FlushAsync();
+            //_stream.Flush();
         }
 
         public override int Read(byte[] buffer, int offset, int count)
@@ -73,7 +83,10 @@ namespace Capnp.Util
             //    throw exception;
             //}
 
-            //_stream.BeginWrite(buffer, offset, count, WriteCallback, null);
+            //if (count >= _asyncThreshold)
+            //    _stream.BeginWrite(buffer, offset, count, WriteCallback, null);
+            //else
+            //    _stream.Write(buffer, offset, count);
         }
 
         protected override void Dispose(bool disposing)