diff --git a/samples/CS10/CS10.csproj b/samples/CS10/CS10.csproj
index ece16dc..a8458e3 100644
--- a/samples/CS10/CS10.csproj
+++ b/samples/CS10/CS10.csproj
@@ -2,7 +2,7 @@
 
     <PropertyGroup>
         <OutputType>Exe</OutputType>
-        <TargetFramework>net8.0</TargetFramework>
+        <TargetFramework>net9.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
     </PropertyGroup>
diff --git a/samples/CS11/CS11.csproj b/samples/CS11/CS11.csproj
index 2a1187d..a8458e3 100644
--- a/samples/CS11/CS11.csproj
+++ b/samples/CS11/CS11.csproj
@@ -2,10 +2,9 @@
 
     <PropertyGroup>
         <OutputType>Exe</OutputType>
-        <TargetFramework>net8.0</TargetFramework>
+        <TargetFramework>net9.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
-        <LangVersion>preview</LangVersion>
     </PropertyGroup>
 
 </Project>
diff --git a/samples/CS7/CS7.csproj b/samples/CS7/CS7.csproj
index ece16dc..a8458e3 100644
--- a/samples/CS7/CS7.csproj
+++ b/samples/CS7/CS7.csproj
@@ -2,7 +2,7 @@
 
     <PropertyGroup>
         <OutputType>Exe</OutputType>
-        <TargetFramework>net8.0</TargetFramework>
+        <TargetFramework>net9.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
     </PropertyGroup>
diff --git a/samples/CS8/CS8.csproj b/samples/CS8/CS8.csproj
index ece16dc..a8458e3 100644
--- a/samples/CS8/CS8.csproj
+++ b/samples/CS8/CS8.csproj
@@ -2,7 +2,7 @@
 
     <PropertyGroup>
         <OutputType>Exe</OutputType>
-        <TargetFramework>net8.0</TargetFramework>
+        <TargetFramework>net9.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
     </PropertyGroup>
diff --git a/samples/CS9/CS9.csproj b/samples/CS9/CS9.csproj
index ece16dc..a8458e3 100644
--- a/samples/CS9/CS9.csproj
+++ b/samples/CS9/CS9.csproj
@@ -2,7 +2,7 @@
 
     <PropertyGroup>
         <OutputType>Exe</OutputType>
-        <TargetFramework>net8.0</TargetFramework>
+        <TargetFramework>net9.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
     </PropertyGroup>