diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 854bbb8..24076c1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -28,10 +28,7 @@ jobs:
     - name: Setup .NET SDK
       uses: actions/setup-dotnet@v4.0.1
       with:
-        dotnet-version: |
-          8.0.x
-          7.0.x
-          6.0.x
+        dotnet-version: 8.0.x
     - name: Build
       run: dotnet build src --configuration Release
     - name: Upload packages
diff --git a/src/Particular.Approvals/Approver.cs b/src/Particular.Approvals/Approver.cs
index d520de8..7a92550 100644
--- a/src/Particular.Approvals/Approver.cs
+++ b/src/Particular.Approvals/Approver.cs
@@ -130,7 +130,7 @@ static void ThrowExceptionWithDiff(string approvedFile, string receivedFile, str
                 var snippetDiffPoint = Enumerable.Range(0, shortestSnippetLength).FirstOrDefault(i => approvedSnippet[i] != receivedSnippet[i]);
 
                 b.Append(new string('-', snippetDiffPoint + approvedStub.Length));
-                b.Append("^");
+                b.Append('^');
             }
 
             throw new Exception(b.ToString());
@@ -140,10 +140,10 @@ static string StringRange(string source, int start, int end)
         {
             if (end >= source.Length)
             {
-                return source.Substring(start);
+                return source[start..];
             }
 
-            return source.Substring(start, end - start);
+            return source[start..end];
         }
 
         static string DisplaySpecialChars(string source) => source.Replace("\r", "\\r").Replace("\n", "\\n").Replace("\t", "\\t");
diff --git a/src/Particular.Approvals/Particular.Approvals.csproj b/src/Particular.Approvals/Particular.Approvals.csproj
index d3c2273..fa8b37a 100644
--- a/src/Particular.Approvals/Particular.Approvals.csproj
+++ b/src/Particular.Approvals/Particular.Approvals.csproj
@@ -1,14 +1,13 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net472;net6.0</TargetFrameworks>
+    <TargetFramework>net8.0</TargetFramework>
     <SignAssembly>true</SignAssembly>
     <AssemblyOriginatorKeyFile>..\NServiceBus.snk</AssemblyOriginatorKeyFile>
   </PropertyGroup>
 
   <ItemGroup>
     <PackageReference Include="Particular.Packaging" Version="4.1.0" PrivateAssets="All" />
-    <PackageReference Include="System.Text.Json" Version="8.0.4" />
   </ItemGroup>
 
 </Project>
diff --git a/src/Tests/Tests.csproj b/src/Tests/Tests.csproj
index 4b5a9ff..0ae8f5e 100644
--- a/src/Tests/Tests.csproj
+++ b/src/Tests/Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net472;net6.0;net7.0;net8.0</TargetFrameworks>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
@@ -9,7 +9,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="GitHubActionsTestLogger" Version="2.3.3" />
+    <PackageReference Include="GitHubActionsTestLogger" Version="2.4.1" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.10.0" />
     <PackageReference Include="NUnit" Version="4.1.0" />
     <PackageReference Include="NUnit.Analyzers" Version="4.2.0" />