diff --git a/Directory.Packages.props b/Directory.Packages.props
index d3e799a82..6a19f850b 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -4,10 +4,10 @@
   </PropertyGroup>
 
   <PropertyGroup>
-    <GrpcVersion>2.35.0</GrpcVersion>
+    <GrpcVersion>2.57.0</GrpcVersion>
     <GrpcCCoreVersion>2.46.6</GrpcCCoreVersion>
-    <MemoryPackVersion>1.9.7</MemoryPackVersion>
-    <MessagePackVersion>2.2.85</MessagePackVersion>
+    <MemoryPackVersion>1.9.16</MemoryPackVersion>
+    <MessagePackVersion>2.5.129</MessagePackVersion>
     <MicrosoftCodeAnalysisVersion>4.3.1</MicrosoftCodeAnalysisVersion>
     <MicrosoftCodeAnalysisVersionUnity>3.9.0</MicrosoftCodeAnalysisVersionUnity>
   </PropertyGroup>
@@ -20,7 +20,6 @@
     <PackageVersion Include="Grpc.Net.Client" Version="$(GrpcVersion)" />
     <PackageVersion Include="MemoryPack" Version="$(MemoryPackVersion)" />
     <PackageVersion Include="MessagePack" Version="$(MessagePackVersion)" />
-    <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="6.0.0" />
     <PackageVersion Include="Microsoft.CodeAnalysis" Version="$(MicrosoftCodeAnalysisVersion)" />
 
     <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="1.1.1" />
@@ -33,6 +32,7 @@
   <ItemGroup>
     <PackageVersion Include="coverlet.collector" Version="3.1.2" />
     <PackageVersion Include="FluentAssertions" Version="6.7.0" />
+    <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="7.0.0" />
     <!-- from https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-tools/nuget/v3/index.json -->
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing.XUnit" Version="1.1.2-beta1.23163.2" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.3.2" />
diff --git a/samples/ChatApp/.config/dotnet-tools.json b/samples/ChatApp/.config/dotnet-tools.json
index d7852f42f..5497a4c24 100644
--- a/samples/ChatApp/.config/dotnet-tools.json
+++ b/samples/ChatApp/.config/dotnet-tools.json
@@ -3,7 +3,7 @@
   "isRoot": true,
   "tools": {
     "messagepack.generator": {
-      "version": "2.4.35",
+      "version": "2.5.129",
       "commands": [
         "mpc"
       ]
diff --git a/samples/ChatApp/Nuget.config b/samples/ChatApp/Nuget.config
deleted file mode 100644
index e05d8fc6f..000000000
--- a/samples/ChatApp/Nuget.config
+++ /dev/null
@@ -1,13 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<configuration>
-  <packageRestore>
-    <add key="enabled" value="true" />
-    <add key="automatic" value="true" />
-  </packageRestore>
-  <packageSources>
-    <clear />
-    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
-    <add key="myget.org roslyn nightly" value="https://dotnet.myget.org/F/roslyn/api/v3/index.json" />
-    <add key="myget.org msbuild nightly" value="https://dotnet.myget.org/F/msbuild/api/v3/index.json" />
-  </packageSources>
-</configuration>
diff --git a/src/MagicOnion.Server/StreamingContext.Duplex.cs b/src/MagicOnion.Server/StreamingContext.Duplex.cs
index 501735ca7..b73571751 100644
--- a/src/MagicOnion.Server/StreamingContext.Duplex.cs
+++ b/src/MagicOnion.Server/StreamingContext.Duplex.cs
@@ -24,7 +24,7 @@ internal DuplexStreamingContext(StreamingServiceContext<TRequest, TResponse> con
     /// <summary>
     /// IServerStreamWriter Methods.
     /// </summary>
-    public WriteOptions WriteOptions
+    public WriteOptions? WriteOptions
     {
         get => innerWriter.WriteOptions;
         set => innerWriter.WriteOptions = value;
diff --git a/src/MagicOnion.Server/StreamingContext.Server.cs b/src/MagicOnion.Server/StreamingContext.Server.cs
index 1b5c181df..a77adabd6 100644
--- a/src/MagicOnion.Server/StreamingContext.Server.cs
+++ b/src/MagicOnion.Server/StreamingContext.Server.cs
@@ -20,7 +20,7 @@ internal ServerStreamingContext(StreamingServiceContext<Nil /* Dummy */, TRespon
 
     public ServiceContext ServiceContext => context;
 
-    public WriteOptions WriteOptions
+    public WriteOptions? WriteOptions
     {
         get => inner.WriteOptions;
         set => inner.WriteOptions = value;
diff --git a/tests/MagicOnion.Client.Tests/ClientFilterTest.cs b/tests/MagicOnion.Client.Tests/ClientFilterTest.cs
index 164747eb9..517075445 100644
--- a/tests/MagicOnion.Client.Tests/ClientFilterTest.cs
+++ b/tests/MagicOnion.Client.Tests/ClientFilterTest.cs
@@ -12,7 +12,7 @@ public async Task ReturnImmediateValue()
             // NOTE: Mock IClientFilter returns a value immediately. (The filter will not call `next`)
             .ReturnsForAnyArgs(ValueTask.FromResult((ResponseContext)ResponseContext<string>.Create("Response", Status.DefaultSuccess, Metadata.Empty, Metadata.Empty)));
         var callInvokerMock = Substitute.For<CallInvoker>();
-        callInvokerMock.AsyncUnaryCall(default(Method<string, string>)!, default, default, default)
+        callInvokerMock.AsyncUnaryCall(default(Method<string, string>)!, default, default, default!)
             .Returns(new AsyncUnaryCall<string>(
                 Task.FromResult("Response"),
                 Task.FromResult(Metadata.Empty),
@@ -40,7 +40,7 @@ public async Task RequestHeaders()
         // Arrange
         var requestHeaders = default(Metadata);
         var callInvokerMock = Substitute.For<CallInvoker>();
-        callInvokerMock.AsyncUnaryCall(default(Method<string, string>)!, default, default, default)
+        callInvokerMock.AsyncUnaryCall(default(Method<string, string>)!, default, default, default!)
             .ReturnsForAnyArgs(x =>
             {
                 requestHeaders = x.Arg<CallOptions>().Headers;
@@ -70,8 +70,8 @@ class ClientFilterTestRequestHeaders : IClientFilter
     {
         public ValueTask<ResponseContext> SendAsync(RequestContext context, Func<RequestContext, ValueTask<ResponseContext>> next)
         {
-            context.CallOptions.Headers.Add("x-header-1", "valueA");
-            context.CallOptions.Headers.Add("x-header-2", "valueB");
+            context.CallOptions.Headers?.Add("x-header-1", "valueA");
+            context.CallOptions.Headers?.Add("x-header-2", "valueB");
             return next(context);
         }
     }
@@ -102,7 +102,7 @@ public async Task FilterChain()
             });
 
         var callInvokerMock = Substitute.For<CallInvoker>();
-        callInvokerMock.AsyncUnaryCall(default(Method<string, string>)!, default, default, default)
+        callInvokerMock.AsyncUnaryCall(default(Method<string, string>)!, default, default, default!)
             .ReturnsForAnyArgs(new AsyncUnaryCall<string>(
                 Task.FromResult("Response"),
                 Task.FromResult(Metadata.Empty),
diff --git a/tests/MagicOnion.Client.Tests/ClientStreamingTest.cs b/tests/MagicOnion.Client.Tests/ClientStreamingTest.cs
index 42483b4f0..a6a41eea9 100644
--- a/tests/MagicOnion.Client.Tests/ClientStreamingTest.cs
+++ b/tests/MagicOnion.Client.Tests/ClientStreamingTest.cs
@@ -32,7 +32,7 @@ public async Task WriteAndCompleteArgumentValueTypeReturnValueType()
                 _ => Status.DefaultSuccess,
                 _ => Metadata.Empty,
                 _ => { },
-                default));
+                new object()));
         var client = MagicOnionClient.Create<IClientStreamingTestService>(callInvokerMock);
 
         // Act
@@ -64,7 +64,7 @@ public async Task WriteAndCompleteArgumentRefTypeReturnValueType()
                 _ => Status.DefaultSuccess,
                 _ => Metadata.Empty,
                 _ => { },
-                default));
+                new object()));
 
         var client = MagicOnionClient.Create<IClientStreamingTestService>(callInvokerMock);
 
@@ -89,7 +89,7 @@ public async Task WriteAndCompleteArgumentValueTypeReturnRefType()
         var clientStreamWriterMock = new MockClientStreamWriter<Box<int>>();
         var callInvokerMock = Substitute.For<CallInvoker>();
         var response = "OK";
-        callInvokerMock.AsyncClientStreamingCall(default(Method<Box<int>, string>), default, default)
+        callInvokerMock.AsyncClientStreamingCall(default(Method<Box<int>, string>)!, default, default)
             .ReturnsForAnyArgs(new AsyncClientStreamingCall<Box<int>, string>(
                 clientStreamWriterMock,
                 Task.FromResult(response),
@@ -97,7 +97,7 @@ public async Task WriteAndCompleteArgumentValueTypeReturnRefType()
                 _ => Status.DefaultSuccess,
                 _ => Metadata.Empty,
                 _ => { },
-                default));
+                new object()));
         var client = MagicOnionClient.Create<IClientStreamingTestService>(callInvokerMock);
 
         // Act
@@ -121,7 +121,7 @@ public async Task WriteAndCompleteArgumentRefTypeReturnRefType()
         var clientStreamWriterMock = new MockClientStreamWriter<Tuple<string, string>>();
         var callInvokerMock = Substitute.For<CallInvoker>();
         var response = "OK";
-        callInvokerMock.AsyncClientStreamingCall(default(Method<Tuple<string, string>, string>), default, default)
+        callInvokerMock.AsyncClientStreamingCall(default(Method<Tuple<string, string>, string>)!, default, default)
             .ReturnsForAnyArgs(new AsyncClientStreamingCall<Tuple<string, string>, string>(
                 clientStreamWriterMock,
                 Task.FromResult(response),
@@ -129,7 +129,7 @@ public async Task WriteAndCompleteArgumentRefTypeReturnRefType()
                 _ => Status.DefaultSuccess,
                 _ => Metadata.Empty,
                 _ => { },
-                default));
+                new object()));
         var client = MagicOnionClient.Create<IClientStreamingTestService>(callInvokerMock);
 
         // Act
diff --git a/tests/MagicOnion.Client.Tests/MockClientStreamWriter.cs b/tests/MagicOnion.Client.Tests/MockClientStreamWriter.cs
index e9d53fe46..3ca100ef9 100644
--- a/tests/MagicOnion.Client.Tests/MockClientStreamWriter.cs
+++ b/tests/MagicOnion.Client.Tests/MockClientStreamWriter.cs
@@ -11,11 +11,11 @@ public Task WriteAsync(T message)
         return Task.CompletedTask;
     }
 
-    public WriteOptions WriteOptions { get; set; } = WriteOptions.Default;
+    public WriteOptions? WriteOptions { get; set; } = WriteOptions.Default;
 
     public Task CompleteAsync()
     {
         Completed = true;
         return Task.CompletedTask;
     }
-}
\ No newline at end of file
+}
diff --git a/tests/MagicOnion.Client.Tests/ServerStreamingTest.cs b/tests/MagicOnion.Client.Tests/ServerStreamingTest.cs
index 7ca935379..35f5e3d2c 100644
--- a/tests/MagicOnion.Client.Tests/ServerStreamingTest.cs
+++ b/tests/MagicOnion.Client.Tests/ServerStreamingTest.cs
@@ -25,7 +25,7 @@ public async Task OneParameterValueTypeReturnValueType()
         var callInvokerMock = Substitute.For<CallInvoker>();
         var arg1 = 123;
         var sendRequest = default(Box<int>);
-        callInvokerMock.AsyncServerStreamingCall(default(Method<Box<int>, Box<int>>)!, default, default, default)
+        callInvokerMock.AsyncServerStreamingCall(default(Method<Box<int>, Box<int>>)!, default, default, Box.Create(default(int)))
             .ReturnsForAnyArgs(x =>
             {
                 var request = x.ArgAt<Box<int>>(3);
@@ -36,7 +36,7 @@ public async Task OneParameterValueTypeReturnValueType()
                     _ => Status.DefaultSuccess,
                     _ => Metadata.Empty,
                     _ => { },
-                    default);
+                    new object());
             });
         var client = MagicOnionClient.Create<IServerStreamingTestService>(callInvokerMock);
 
@@ -67,7 +67,7 @@ public async Task OneParameterRefTypeReturnValueType()
         var callInvokerMock = Substitute.For<CallInvoker>();
         var arg1 = "FooBar";
         var sendRequest = default(string);
-        callInvokerMock.AsyncServerStreamingCall(default(Method<string, Box<int>>)!, default, default, default)
+        callInvokerMock.AsyncServerStreamingCall(default(Method<string, Box<int>>)!, default, default, default!)
             .ReturnsForAnyArgs(x =>
             {
                 var request = x.ArgAt<string>(3);
@@ -78,7 +78,7 @@ public async Task OneParameterRefTypeReturnValueType()
                     _ => Status.DefaultSuccess,
                     _ => Metadata.Empty,
                     _ => { },
-                    default);
+                    new object());
             });
         var client = MagicOnionClient.Create<IServerStreamingTestService>(callInvokerMock);
 
@@ -109,7 +109,7 @@ public async Task OneParameterValueTypeReturnRefType()
         var callInvokerMock = Substitute.For<CallInvoker>();
         var arg1 = 123;
         var sendRequest = default(Box<int>);
-        callInvokerMock.AsyncServerStreamingCall(default(Method<Box<int>, string>)!, default, default, default)
+        callInvokerMock.AsyncServerStreamingCall(default(Method<Box<int>, string>)!, default, default, default!)
             .ReturnsForAnyArgs(x =>
             {
                 var request = x.ArgAt<Box<int>>(3);
@@ -120,7 +120,7 @@ public async Task OneParameterValueTypeReturnRefType()
                     _ => Status.DefaultSuccess,
                     _ => Metadata.Empty,
                     _ => { },
-                    default);
+                    new object());
             });
         var client = MagicOnionClient.Create<IServerStreamingTestService>(callInvokerMock);
 
@@ -151,7 +151,7 @@ public async Task OneParameterRefTypeReturnRefType()
         var callInvokerMock = Substitute.For<CallInvoker>();
         var arg1 = "FooBar";
         var sendRequest = default(string);
-        callInvokerMock.AsyncServerStreamingCall(default(Method<string, string>)!, default, default, default)
+        callInvokerMock.AsyncServerStreamingCall(default(Method<string, string>)!, default, default, default!)
             .ReturnsForAnyArgs(x =>
             {
                 var request = x.ArgAt<string>(3);
@@ -162,7 +162,7 @@ public async Task OneParameterRefTypeReturnRefType()
                     _ => Status.DefaultSuccess,
                     _ => Metadata.Empty,
                     _ => { },
-                    default);
+                    new object());
             });
         var client = MagicOnionClient.Create<IServerStreamingTestService>(callInvokerMock);
 
diff --git a/tests/MagicOnion.Client.Tests/UnaryTest.cs b/tests/MagicOnion.Client.Tests/UnaryTest.cs
index 5a6c75286..68fcf514a 100644
--- a/tests/MagicOnion.Client.Tests/UnaryTest.cs
+++ b/tests/MagicOnion.Client.Tests/UnaryTest.cs
@@ -25,7 +25,7 @@ public async Task Clone_WithOptions()
         // Arrange
         var actualCallOptions = default(CallOptions);
         var callInvokerMock = Substitute.For<CallInvoker>();
-        callInvokerMock.AsyncUnaryCall(default(Method<Box<Nil>, Box<Nil>>)!, default, default, default)
+        callInvokerMock.AsyncUnaryCall(default(Method<Box<Nil>, Box<Nil>>)!, default, default, default!)
             .ReturnsForAnyArgs(x =>
             {
                 // method, host, callOptions, request
@@ -70,7 +70,7 @@ public async Task Clone_WithCancellationToken()
         var cts = new CancellationTokenSource();
         var actualCancellationToken = default(CancellationToken);
         var callInvokerMock = Substitute.For<CallInvoker>();
-        callInvokerMock.AsyncUnaryCall(default(Method<Box<Nil>, Box<Nil>>)!, default, default, default)
+        callInvokerMock.AsyncUnaryCall(default(Method<Box<Nil>, Box<Nil>>)!, default, default, default!)
             .ReturnsForAnyArgs(x =>
             {
                 // method, host, callOptions, request
@@ -96,7 +96,7 @@ public async Task Clone_WithHeaders()
         // Arrange
         var actualHeaders = default(Metadata);
         var callInvokerMock = Substitute.For<CallInvoker>();
-        callInvokerMock.AsyncUnaryCall(default(Method<Box<Nil>, Box<Nil>>)!, default, default, default)
+        callInvokerMock.AsyncUnaryCall(default(Method<Box<Nil>, Box<Nil>>)!, default, default, default!)
             .ReturnsForAnyArgs(x =>
             {
                 // method, host, callOptions, request
@@ -122,7 +122,7 @@ public async Task ParameterlessRequestsNil()
         // Arrange
         var serializedResponse = new ReadOnlyMemory<byte>();
         var callInvokerMock = Substitute.For<CallInvoker>();
-        callInvokerMock.AsyncUnaryCall(default(Method<Box<Nil>, Box<Nil>>)!, default, default, default)
+        callInvokerMock.AsyncUnaryCall(default(Method<Box<Nil>, Box<Nil>>)!, default, default, default!)
             .ReturnsForAnyArgs(x =>
             {
                 // method, host, callOptions, request
diff --git a/tests/MagicOnion.Integration.Tests/ClientFilterTest.cs b/tests/MagicOnion.Integration.Tests/ClientFilterTest.cs
index 6df9e70a7..5bcc651f9 100644
--- a/tests/MagicOnion.Integration.Tests/ClientFilterTest.cs
+++ b/tests/MagicOnion.Integration.Tests/ClientFilterTest.cs
@@ -138,8 +138,8 @@ public class AppendHeaderFilter : IClientFilter
     public async ValueTask<ResponseContext> SendAsync(RequestContext context, Func<RequestContext, ValueTask<ResponseContext>> next)
     {
         var header = context.CallOptions.Headers;
-        header.Add("x-foo", "abcdefg");
-        header.Add("x-bar", "hijklmn");
+        header?.Add("x-foo", "abcdefg");
+        header?.Add("x-bar", "hijklmn");
 
         var response = await next(context);
         return response;