diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index cb4ede8..9ff5a8e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -22,24 +22,24 @@ jobs:
       fail-fast: false
     steps:
       - name: Checkout
-        uses: actions/checkout@v3.2.0
+        uses: actions/checkout@v4.1.1
         with:
           fetch-depth: 0
       - name: Setup .dotnet
-        uses: actions/setup-dotnet@v3.0.3
+        uses: actions/setup-dotnet@v4.0.0
         with:
-         dotnet-version: |
-           7.0.x
-           6.0.x
-           3.1.x
+          dotnet-version: |
+            8.0.x
+            7.0.x
+            6.0.x
       - name: Build
         run: dotnet build src --configuration Release
       - name: Upload packages
         if: matrix.name == 'Windows'
-        uses: actions/upload-artifact@v3.1.1
+        uses: actions/upload-artifact@v4.3.1
         with:
           name: NuGet packages
           path: nugets/
           retention-days: 7
       - name: Run tests
-        uses: Particular/run-tests-action@v1.4.0
+        uses: Particular/run-tests-action@v1.7.0
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 9c1afa5..b0cf00b 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -11,13 +11,13 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - name: Checkout
-        uses: actions/checkout@v3.2.0
+        uses: actions/checkout@v4.1.1
         with:
           fetch-depth: 0
       - name: Setup .NET SDK
-        uses: actions/setup-dotnet@v3.0.3
+        uses: actions/setup-dotnet@v4.0.0
         with:
-          dotnet-version: 7.0.x            
+          dotnet-version: 8.0.x
       - name: Build
         run: dotnet build src --configuration Release
       - name: Sign NuGet packages
@@ -28,12 +28,13 @@ jobs:
           client-secret: ${{ secrets.AZURE_KEY_VAULT_CLIENT_SECRET }}
           certificate-name: ${{ secrets.AZURE_KEY_VAULT_CERTIFICATE_NAME }}
       - name: Publish artifacts
-        uses: actions/upload-artifact@v3.1.1
+        uses: actions/upload-artifact@v4.3.1
         with:
           name: nugets
           path: nugets/*
           retention-days: 1
       - name: Deploy
-        uses: Particular/push-octopus-package-action@v1.0.0
+        # Does not follow standard practice of targeting explicit versions because configuration is tightly coupled to Octopus Deploy configuration
+        uses: Particular/push-octopus-package-action@main
         with:
           octopus-deploy-api-key: ${{ secrets.OCTOPUS_DEPLOY_API_KEY }}
diff --git a/src/NServiceBus.Heartbeat.AcceptanceTests/EndpointTemplates/DefaultServer.cs b/src/NServiceBus.Heartbeat.AcceptanceTests/EndpointTemplates/DefaultServer.cs
index 8f87b6b..587f99e 100644
--- a/src/NServiceBus.Heartbeat.AcceptanceTests/EndpointTemplates/DefaultServer.cs
+++ b/src/NServiceBus.Heartbeat.AcceptanceTests/EndpointTemplates/DefaultServer.cs
@@ -36,7 +36,7 @@ public async Task<EndpointConfiguration> GetConfiguration(RunDescriptor runDescr
             recoverability.Delayed(delayed => delayed.NumberOfRetries(0));
             recoverability.Immediate(immediate => immediate.NumberOfRetries(0));
             configuration.SendFailedMessagesTo("error");
-            configuration.UseSerialization<NewtonsoftSerializer>();
+            configuration.UseSerialization<NewtonsoftJsonSerializer>();
 
             await configuration.DefineTransport(runDescriptor, endpointConfiguration).ConfigureAwait(false);
 
diff --git a/src/NServiceBus.Heartbeat.AcceptanceTests/NServiceBus.Heartbeat.AcceptanceTests.csproj b/src/NServiceBus.Heartbeat.AcceptanceTests/NServiceBus.Heartbeat.AcceptanceTests.csproj
index 64fb6e5..b8a330d 100644
--- a/src/NServiceBus.Heartbeat.AcceptanceTests/NServiceBus.Heartbeat.AcceptanceTests.csproj
+++ b/src/NServiceBus.Heartbeat.AcceptanceTests/NServiceBus.Heartbeat.AcceptanceTests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net452;netcoreapp3.1;net6.0;net7.0</TargetFrameworks>
+    <TargetFrameworks>net481;net6.0;net7.0;net8.0</TargetFrameworks>
     <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
   </PropertyGroup>
 
@@ -11,14 +11,14 @@
 
   <ItemGroup>
     <PackageReference Include="NServiceBus.AcceptanceTesting" Version="7.2.3" />
-    <PackageReference Include="NServiceBus.Newtonsoft.Json" Version="2.1.0" />
+    <PackageReference Include="NServiceBus.Newtonsoft.Json" Version="2.4.0" />
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="GitHubActionsTestLogger" Version="1.2.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.9.4" />
-    <PackageReference Include="NUnit" Version="3.13.1" />
-    <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
+    <PackageReference Include="GitHubActionsTestLogger" Version="2.3.3" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
+    <PackageReference Include="NUnit" Version="3.14.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.5.0" />
   </ItemGroup>
 
 </Project>
\ No newline at end of file
diff --git a/src/NServiceBus.Heartbeat.Sample/NServiceBus.Heartbeat.Sample.csproj b/src/NServiceBus.Heartbeat.Sample/NServiceBus.Heartbeat.Sample.csproj
index ec0867b..cc6c41f 100644
--- a/src/NServiceBus.Heartbeat.Sample/NServiceBus.Heartbeat.Sample.csproj
+++ b/src/NServiceBus.Heartbeat.Sample/NServiceBus.Heartbeat.Sample.csproj
@@ -11,7 +11,7 @@
 
   <ItemGroup>
     <PackageReference Include="NServiceBus" Version="7.1.5" />
-    <PackageReference Include="NServiceBus.Newtonsoft.Json" Version="2.1.0" />
+    <PackageReference Include="NServiceBus.Newtonsoft.Json" Version="2.4.0" />
   </ItemGroup>
 
 </Project>
\ No newline at end of file
diff --git a/src/NServiceBus.Heartbeat.Sample/Program.cs b/src/NServiceBus.Heartbeat.Sample/Program.cs
index e44a8f4..5f6ff4b 100644
--- a/src/NServiceBus.Heartbeat.Sample/Program.cs
+++ b/src/NServiceBus.Heartbeat.Sample/Program.cs
@@ -13,7 +13,7 @@ static async Task AsyncMain()
     {
         Console.Title = "NServiceBus.Heartbeat.Sample";
         var endpointConfiguration = new EndpointConfiguration("NServiceBus.Heartbeat.Sample");
-        endpointConfiguration.UseSerialization<NewtonsoftSerializer>();
+        endpointConfiguration.UseSerialization<NewtonsoftJsonSerializer>();
         endpointConfiguration.UseTransport<LearningTransport>();
         endpointConfiguration.SendFailedMessagesTo("error");
         endpointConfiguration.SendHeartbeatTo("Particular.ServiceControl");
diff --git a/src/NServiceBus.Heartbeat.Tests/NServiceBus.Heartbeat.Tests.csproj b/src/NServiceBus.Heartbeat.Tests/NServiceBus.Heartbeat.Tests.csproj
index 421eafa..dacfd1b 100644
--- a/src/NServiceBus.Heartbeat.Tests/NServiceBus.Heartbeat.Tests.csproj
+++ b/src/NServiceBus.Heartbeat.Tests/NServiceBus.Heartbeat.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net452;netcoreapp3.1;net6.0;net7.0</TargetFrameworks>
+    <TargetFrameworks>net481;net6.0;net7.0;net8.0</TargetFrameworks>
     <SignAssembly>true</SignAssembly>
     <AssemblyOriginatorKeyFile>$(SolutionDir)NServiceBus.snk</AssemblyOriginatorKeyFile>
     <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
@@ -16,12 +16,12 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="GitHubActionsTestLogger" Version="1.2.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.9.4" />
-    <PackageReference Include="NUnit" Version="3.13.1" />
-    <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
+    <PackageReference Include="GitHubActionsTestLogger" Version="2.3.3" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
+    <PackageReference Include="NUnit" Version="3.14.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.5.0" />
     <PackageReference Include="PublicApiGenerator" Version="9.3.0" />
-    <PackageReference Include="Particular.Approvals" Version="0.2.0" />
+    <PackageReference Include="Particular.Approvals" Version="0.3.0" />
   </ItemGroup>
 
 </Project>
\ No newline at end of file