diff --git a/test/netstd/Client/Client.csproj b/test/netstd/Client/Client.csproj
index 828ea73..d3504d4 100644
--- a/test/netstd/Client/Client.csproj
+++ b/test/netstd/Client/Client.csproj
@@ -20,6 +20,7 @@
 
   <PropertyGroup>
     <TargetFramework>net5.0</TargetFramework>
+    <LangVersion>9.0</LangVersion>
     <AssemblyName>Client</AssemblyName>
     <PackageId>Client</PackageId>
     <OutputType>Exe</OutputType>
diff --git a/test/netstd/Client/Program.cs b/test/netstd/Client/Program.cs
index 7e502cd..bcc02a2 100644
--- a/test/netstd/Client/Program.cs
+++ b/test/netstd/Client/Program.cs
@@ -18,6 +18,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Runtime.InteropServices;
 using ThriftTest;
 
 namespace Client
@@ -26,8 +27,8 @@
     {
         public static int Main(string[] args)
         {
-            if (OperatingSystem.IsWindows())
-            { 
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            {
                 try
                 {
                     Console.SetBufferSize(Console.BufferWidth, 4096);
@@ -69,5 +70,3 @@
         }
     }
 }
-
-
diff --git a/test/netstd/Server/Program.cs b/test/netstd/Server/Program.cs
index 0052bce..8f1f36d 100644
--- a/test/netstd/Server/Program.cs
+++ b/test/netstd/Server/Program.cs
@@ -18,6 +18,7 @@
 using System;
 using System.Linq;
 using System.Collections.Generic;
+using System.Runtime.InteropServices;
 using ThriftTest;
 
 namespace Server
@@ -26,7 +27,7 @@
     {
         public static int Main(string[] args)
         {
-            if (OperatingSystem.IsWindows())
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
             {
                 try
                 {
@@ -65,5 +66,3 @@
         }
     }
 }
-
-
diff --git a/test/netstd/Server/Server.csproj b/test/netstd/Server/Server.csproj
index fe1c394..e2ec93c 100644
--- a/test/netstd/Server/Server.csproj
+++ b/test/netstd/Server/Server.csproj
@@ -20,6 +20,7 @@
 
   <PropertyGroup>
     <TargetFramework>net5.0</TargetFramework>
+    <LangVersion>9.0</LangVersion>
     <AssemblyName>Server</AssemblyName>
     <PackageId>Server</PackageId>
     <OutputType>Exe</OutputType>
diff --git a/tutorial/netstd/Client/Client.csproj b/tutorial/netstd/Client/Client.csproj
index 8a923e1..e91b7a9 100644
--- a/tutorial/netstd/Client/Client.csproj
+++ b/tutorial/netstd/Client/Client.csproj
@@ -20,6 +20,7 @@
 
   <PropertyGroup>
     <TargetFramework>net5.0</TargetFramework>
+    <LangVersion>9.0</LangVersion>
     <AssemblyName>Client</AssemblyName>
     <PackageId>Client</PackageId>
     <OutputType>Exe</OutputType>
diff --git a/tutorial/netstd/Server/Server.csproj b/tutorial/netstd/Server/Server.csproj
index 9da3249..b63967b 100644
--- a/tutorial/netstd/Server/Server.csproj
+++ b/tutorial/netstd/Server/Server.csproj
@@ -20,6 +20,7 @@
 
   <PropertyGroup>
     <TargetFramework>net5.0</TargetFramework>
+    <LangVersion>9.0</LangVersion>
     <AssemblyName>Server</AssemblyName>
     <PackageId>Server</PackageId>
     <OutputType>Exe</OutputType>