diff --git a/dotnet/Directory.Build.props b/dotnet/Directory.Build.props
index 22d72bf2ad65..1e84f78232ad 100644
--- a/dotnet/Directory.Build.props
+++ b/dotnet/Directory.Build.props
@@ -3,8 +3,8 @@
   <Import Project="./eng/MetaInfo.props" />
   <Import Project="./eng/Sign.props" />
   <PropertyGroup>
-    <PackageTargetFrameworks>netstandard2.0;net9.0</PackageTargetFrameworks>
-    <TestTargetFrameworks>net9.0</TestTargetFrameworks>
+    <PackageTargetFrameworks>netstandard2.0;net8.0</PackageTargetFrameworks>
+    <TestTargetFrameworks>net8.0</TestTargetFrameworks>
     <LangVersion>preview</LangVersion>
 	  <Nullable>enable</Nullable>
     <SignAssembly>True</SignAssembly>
diff --git a/dotnet/Directory.Packages.props b/dotnet/Directory.Packages.props
index 581fca20d99f..5321860e427f 100644
--- a/dotnet/Directory.Packages.props
+++ b/dotnet/Directory.Packages.props
@@ -118,6 +118,6 @@
     <PackageVersion Include="xunit.runner.visualstudio" Version="2.8.2" />
     <PackageVersion Include="Moq" Version="4.20.72" />
     <PackageVersion Include="Microsoft.PowerShell.SDK" Version="7.4.5" />
-    <PackageVersion Include="Microsoft.AspNetCore.TestHost" Version="9.0.0" />
+    <PackageVersion Include="Microsoft.AspNetCore.TestHost" Version="8.0.0" />
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/dotnet/src/AutoGen.WebAPI/AutoGen.WebAPI.csproj b/dotnet/src/AutoGen.WebAPI/AutoGen.WebAPI.csproj
index 78c99722657d..fe549d969b3a 100644
--- a/dotnet/src/AutoGen.WebAPI/AutoGen.WebAPI.csproj
+++ b/dotnet/src/AutoGen.WebAPI/AutoGen.WebAPI.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net9.0</TargetFrameworks>
+    <TargetFrameworks>net8.0</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <NoWarn>$(NoWarn);CS1591;CS1573;CA1852</NoWarn>
   </PropertyGroup>