diff --git a/Refit.HttpClientFactory/Refit.HttpClientFactory.csproj b/Refit.HttpClientFactory/Refit.HttpClientFactory.csproj
index 5df74ca3c..4aad7255f 100644
--- a/Refit.HttpClientFactory/Refit.HttpClientFactory.csproj
+++ b/Refit.HttpClientFactory/Refit.HttpClientFactory.csproj
@@ -1,9 +1,9 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <Product>Refit HTTP Client Factory Extensions</Product>
     <Description>Refit HTTP Client Factory Extensions</Description>
-    <TargetFrameworks>netstandard2.0;net462;net6.0;net7.0</TargetFrameworks>
+    <TargetFrameworks>net462;netstandard2.0;net6.0;net7.0;net8.0</TargetFrameworks>
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
diff --git a/Refit.Newtonsoft.Json/Refit.Newtonsoft.Json.csproj b/Refit.Newtonsoft.Json/Refit.Newtonsoft.Json.csproj
index 277de4e82..7c7174142 100644
--- a/Refit.Newtonsoft.Json/Refit.Newtonsoft.Json.csproj
+++ b/Refit.Newtonsoft.Json/Refit.Newtonsoft.Json.csproj
@@ -3,15 +3,14 @@
   <PropertyGroup>
     <Product>Refit Serializer for Newtonsoft.Json ($(TargetFramework))</Product>
     <Description>Refit Serializers for Newtonsoft.Json</Description>
-    <TargetFrameworks>netstandard2.0;net462;net6.0;net7.0</TargetFrameworks>
+    <TargetFrameworks>net462;netstandard2.0;netstandard2.1</TargetFrameworks>
     <GenerateDocumentationFile Condition=" '$(Configuration)' == 'Release' ">true</GenerateDocumentationFile>
     <RootNamespace>Refit</RootNamespace>
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
-    
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />    
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == 'net462'">
diff --git a/Refit.Tests/Refit.Tests.csproj b/Refit.Tests/Refit.Tests.csproj
index 72bcd9444..074250ac6 100644
--- a/Refit.Tests/Refit.Tests.csproj
+++ b/Refit.Tests/Refit.Tests.csproj
@@ -1,9 +1,9 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <Import Project="..\Refit\targets\refit.props" />
   
   <PropertyGroup>
-    <TargetFrameworks>net462;net6.0;net7.0</TargetFrameworks>
+    <TargetFrameworks>net462;net6.0;net7.0;net8.0</TargetFrameworks>
     <Deterministic>false</Deterministic> <!-- Some tests rely on CallerFilePath -->
     <RestoreAdditionalProjectSources>https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-tools/nuget/v3/index.json</RestoreAdditionalProjectSources>
   </PropertyGroup>
@@ -11,7 +11,7 @@
   <ItemGroup>
     <EmbeddedResource Include="Test Files\Test.pdf" />
   </ItemGroup>
-
+  
   <ItemGroup>
     <PackageReference Include="coverlet.msbuild" Version="6.0.2" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
@@ -19,8 +19,8 @@
     <PackageReference Include="xunit.runner.visualstudio" Version="2.8.0" />
     <PackageReference Include="System.Reactive" Version="6.0.0" />    
     <PackageReference Include="Microsoft.AspNetCore.WebUtilities" Version="2.2.0" />
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.7.0" />
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing.XUnit" Version="1.1.2-beta1.23509.1" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.9.2" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.SourceGenerators.Testing" Version="1.1.2-beta1.24169.1" />
     <PackageReference Include="RichardSzalay.MockHttp" Version="6.0.0" />
     <ProjectReference Include="..\Refit.HttpClientFactory\Refit.HttpClientFactory.csproj" />
     <ProjectReference Include="..\Refit.Newtonsoft.Json\Refit.Newtonsoft.Json.csproj" />
@@ -29,9 +29,5 @@
     <ProjectReference Include="..\InterfaceStubGenerator.Roslyn40\InterfaceStubGenerator.Roslyn40.csproj" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetFramework)' == 'net461' ">
-    <Reference Include="System.Net.Http" />
-  </ItemGroup>
-
   <Import Project="..\Refit\targets\refit.targets" />
 </Project>
diff --git a/Refit.Tests/Verifiers/CSharpIncrementalSourceGeneratorVerifier`1+Test.cs b/Refit.Tests/Verifiers/CSharpIncrementalSourceGeneratorVerifier`1+Test.cs
index be8adea56..2e490360f 100644
--- a/Refit.Tests/Verifiers/CSharpIncrementalSourceGeneratorVerifier`1+Test.cs
+++ b/Refit.Tests/Verifiers/CSharpIncrementalSourceGeneratorVerifier`1+Test.cs
@@ -4,14 +4,13 @@
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Testing;
 using Microsoft.CodeAnalysis.Testing;
-using Microsoft.CodeAnalysis.Testing.Verifiers;
 
 namespace Refit.Tests
 {
     public static partial class CSharpIncrementalSourceGeneratorVerifier<TIncrementalGenerator>
         where TIncrementalGenerator : IIncrementalGenerator, new()
     {
-        public class Test : CSharpSourceGeneratorTest<EmptySourceGeneratorProvider, XUnitVerifier>
+        public class Test : CSharpSourceGeneratorTest<EmptySourceGeneratorProvider, DefaultVerifier>
         {
             public Test()
             {
diff --git a/Refit.Tests/Verifiers/CSharpSourceGeneratorVerifier`1+Test.cs b/Refit.Tests/Verifiers/CSharpSourceGeneratorVerifier`1+Test.cs
index 0f1d672b2..3cc8ffe93 100644
--- a/Refit.Tests/Verifiers/CSharpSourceGeneratorVerifier`1+Test.cs
+++ b/Refit.Tests/Verifiers/CSharpSourceGeneratorVerifier`1+Test.cs
@@ -2,14 +2,14 @@
 
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp.Testing;
-using Microsoft.CodeAnalysis.Testing.Verifiers;
+using Microsoft.CodeAnalysis.Testing;
 
 namespace Refit.Tests
 {
     public static partial class CSharpSourceGeneratorVerifier<TSourceGenerator>
         where TSourceGenerator : ISourceGenerator, new()
     {
-        public class Test : CSharpSourceGeneratorTest<TSourceGenerator, XUnitVerifier>
+        public class Test : CSharpSourceGeneratorTest<TSourceGenerator, DefaultVerifier>
         {
             public Test()
             {
diff --git a/Refit.Xml/Refit.Xml.csproj b/Refit.Xml/Refit.Xml.csproj
index 097a4b149..9a3c6647e 100644
--- a/Refit.Xml/Refit.Xml.csproj
+++ b/Refit.Xml/Refit.Xml.csproj
@@ -3,7 +3,7 @@
   <PropertyGroup>
     <Product>Refit Xml Serializer ($(TargetFramework))</Product>
     <Description>Refit Serializers for Xml</Description>
-    <TargetFrameworks>netstandard2.0;net462;net6.0;net7.0</TargetFrameworks>
+    <TargetFrameworks>net462;netstandard2.0;netstandard2.1</TargetFrameworks>
     <GenerateDocumentationFile Condition=" '$(Configuration)' == 'Release' ">true</GenerateDocumentationFile>
     <RootNamespace>Refit</RootNamespace>
     <Nullable>enable</Nullable>
diff --git a/Refit/Refit.csproj b/Refit/Refit.csproj
index 47f815c4b..675fbef69 100644
--- a/Refit/Refit.csproj
+++ b/Refit/Refit.csproj
@@ -1,18 +1,21 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <Product>Refit ($(TargetFramework))</Product>
-    <TargetFrameworks>netstandard2.0;netstandard2.1;net462;net6.0;net7.0</TargetFrameworks>
+    <TargetFrameworks>net462;netstandard2.0;netstandard2.1</TargetFrameworks>
     <GenerateDocumentationFile Condition=" '$(Configuration)' == 'Release' ">true</GenerateDocumentationFile>
 
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
-  <ItemGroup Condition="'$(TargetFramework)' == 'net462' or '$(TargetFramework)' == 'netstandard2.0' or '$(TargetFramework)' == 'netstandard2.1'">
-    <PackageReference Include="System.Text.Json" Version="8.0.3" />
+  <ItemGroup>
     <PackageReference Include="System.Net.Http.Json" Version="8.0.0" />
   </ItemGroup>
 
+  <ItemGroup Condition="'$(TargetFramework)' != 'netstandard2.1'">
+    <PackageReference Include="System.Text.Json" Version="8.0.3" />
+  </ItemGroup>
+
   <ItemGroup Condition="'$(TargetFramework)' == 'net462'">
     <Reference Include="System.Web" />
     <PackageReference Include="System.Net.Http" Version="4.3.4" />