diff --git a/.github/workflows/cd-aspnetcore-abstractions.yml b/.github/workflows/cd-aspnetcore-abstractions.yml
new file mode 100644
index 0000000..323c00d
--- /dev/null
+++ b/.github/workflows/cd-aspnetcore-abstractions.yml
@@ -0,0 +1,43 @@
+name: Lib.AspNetCore.ServerTiming.Abstractions - CD
+on:
+  push:
+    tags:
+    - "aspnetcore-abstractions-v[0-9]+.[0-9]+.[0-9]+"
+jobs:
+  deployment:
+    runs-on: windows-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+    - name: Extract VERSION
+      run: echo "VERSION=${GITHUB_REF/refs\/tags\/aspnetcore-abstractions-v/}" >> $GITHUB_ENV
+      shell: bash
+    - name: Setup .NET Core 2.1 SDK
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: '2.1.x'
+    - name: Setup .NET Core 3.1 SDK
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: '3.1.x'
+    - name: Setup .NET 5.0 SDK
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: '5.0.x'
+    - name: Setup .NET 6.0 SDK
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: '6.0.x'
+    - name: Restore
+      run: dotnet restore
+    - name: Build
+      run: dotnet build --configuration Release --no-restore
+    - name: Test
+      run: dotnet test --configuration Release --no-build
+    - name: Pack
+      run: dotnet pack --configuration Release --no-build
+    - name: NuGet Push Lib.AspNetCore.ServerTiming.Abstractions
+      run: dotnet nuget push Lib.AspNetCore.ServerTiming.Abstractions/bin/Release/Lib.AspNetCore.ServerTiming.Abstractions.${VERSION}.nupkg --source https://api.nuget.org/v3/index.json --api-key ${NUGET_API_KEY}
+      shell: bash
+      env:
+        NUGET_API_KEY: ${{ secrets.NUGET_API_KEY }}
\ No newline at end of file
diff --git a/.github/workflows/cd.yml b/.github/workflows/cd-aspnetcore.yml
similarity index 88%
rename from .github/workflows/cd.yml
rename to .github/workflows/cd-aspnetcore.yml
index 841e6ed..8c71912 100644
--- a/.github/workflows/cd.yml
+++ b/.github/workflows/cd-aspnetcore.yml
@@ -1,8 +1,8 @@
-name: CD
+name: Lib.AspNetCore.ServerTiming - CD
 on:
   push:
     tags:
-    - "v[0-9]+.[0-9]+.[0-9]+"
+    - "aspnetcore-v[0-9]+.[0-9]+.[0-9]+"
 jobs:
   deployment:
     runs-on: windows-latest
@@ -10,7 +10,7 @@ jobs:
     - name: Checkout
       uses: actions/checkout@v2
     - name: Extract VERSION
-      run: echo "VERSION=${GITHUB_REF/refs\/tags\/v/}" >> $GITHUB_ENV
+      run: echo "VERSION=${GITHUB_REF/refs\/tags\/aspnetcore-v/}" >> $GITHUB_ENV
       shell: bash
     - name: Setup .NET Core 2.1 SDK
       uses: actions/setup-dotnet@v1
diff --git a/DocFx.AspNetCore.ServerTiming/docfx.json b/DocFx.AspNetCore.ServerTiming/docfx.json
index 792ce7a..e339301 100644
--- a/DocFx.AspNetCore.ServerTiming/docfx.json
+++ b/DocFx.AspNetCore.ServerTiming/docfx.json
@@ -4,6 +4,7 @@
       "src": [
         {
           "files": [
+            "Lib.AspNetCore.ServerTiming.Abstractions/Lib.AspNetCore.ServerTiming.Abstractions.csproj",
             "Lib.AspNetCore.ServerTiming/Lib.AspNetCore.ServerTiming.csproj"
           ],
           "exclude": [ "**/bin/**", "**/obj/**" ],
diff --git a/Lib.AspNetCore.ServerTiming/Filters/IServerTimingMetricFilter.cs b/Lib.AspNetCore.ServerTiming.Abstractions/Filters/IServerTimingMetricFilter.cs
similarity index 100%
rename from Lib.AspNetCore.ServerTiming/Filters/IServerTimingMetricFilter.cs
rename to Lib.AspNetCore.ServerTiming.Abstractions/Filters/IServerTimingMetricFilter.cs
diff --git a/Lib.AspNetCore.ServerTiming/Http/Headers/ServerTimingMetric.cs b/Lib.AspNetCore.ServerTiming.Abstractions/Http/Headers/ServerTimingMetric.cs
similarity index 100%
rename from Lib.AspNetCore.ServerTiming/Http/Headers/ServerTimingMetric.cs
rename to Lib.AspNetCore.ServerTiming.Abstractions/Http/Headers/ServerTimingMetric.cs
diff --git a/Lib.AspNetCore.ServerTiming/IServerTiming.cs b/Lib.AspNetCore.ServerTiming.Abstractions/IServerTiming.cs
similarity index 100%
rename from Lib.AspNetCore.ServerTiming/IServerTiming.cs
rename to Lib.AspNetCore.ServerTiming.Abstractions/IServerTiming.cs
diff --git a/Lib.AspNetCore.ServerTiming.Abstractions/Lib.AspNetCore.ServerTiming.Abstractions.csproj b/Lib.AspNetCore.ServerTiming.Abstractions/Lib.AspNetCore.ServerTiming.Abstractions.csproj
new file mode 100644
index 0000000..eee9849
--- /dev/null
+++ b/Lib.AspNetCore.ServerTiming.Abstractions/Lib.AspNetCore.ServerTiming.Abstractions.csproj
@@ -0,0 +1,37 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <Description>Lib.AspNetCore.ServerTiming.Abstractions provides abstractions for Lib.AspNetCore.ServerTiming, a library which provides Server Timing API support for ASP.NET Core.</Description>
+    <Copyright>Copyright © 2022 Tomasz Pęczek</Copyright>
+    <VersionPrefix>1.0.0</VersionPrefix>
+    <Authors>Tomasz Pęczek</Authors>
+    <TargetFrameworks>netcoreapp2.1;netcoreapp3.1;net5.0;net6.0;net461</TargetFrameworks>
+    <AssemblyTitle>Lib.AspNetCore.ServerTiming.Abstractions</AssemblyTitle>
+    <AssemblyName>Lib.AspNetCore.ServerTiming.Abstractions</AssemblyName>
+    <PackageId>Lib.AspNetCore.ServerTiming.Abstractions</PackageId>
+    <PackageTags>aspnetcore;servertiming;performance</PackageTags>
+    <PackageProjectUrl>https://github.com/tpeczek/Lib.AspNetCore.ServerTiming</PackageProjectUrl>
+    <PackageLicenseExpression>MIT</PackageLicenseExpression>
+    <PackageReadmeFile>README.md</PackageReadmeFile>
+    <RepositoryType>git</RepositoryType>
+    <RepositoryUrl>git://github.com/tpeczek/Lib.AspNetCore.ServerTiming</RepositoryUrl>
+    <GenerateAssemblyTitleAttribute>true</GenerateAssemblyTitleAttribute>
+    <GenerateAssemblyDescriptionAttribute>true</GenerateAssemblyDescriptionAttribute>
+    <GenerateAssemblyProductAttribute>true</GenerateAssemblyProductAttribute>
+    <GenerateAssemblyCopyrightAttribute>true</GenerateAssemblyCopyrightAttribute>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <LangVersion>latest</LangVersion>
+  </PropertyGroup>
+  <ItemGroup>
+    <None Include="..\README.md" Pack="true" PackagePath="\" />
+  </ItemGroup>
+  <ItemGroup Condition="('$(TargetFramework)' == 'netcoreapp2.1') Or ('$(TargetFramework)' == 'net461')">
+    <PackageReference Include="Microsoft.AspNetCore.Http" Version="[2.1.0,3.0.0)" />
+  </ItemGroup>
+  <ItemGroup Condition="('$(TargetFramework)' != 'netcoreapp2.1') And ('$(TargetFramework)' != 'net461')">
+    <FrameworkReference Include="Microsoft.AspNetCore.App" />
+  </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="DotNet.ReproducibleBuilds" Version="0.1.66" PrivateAssets="All" />
+  </ItemGroup>
+</Project>
\ No newline at end of file
diff --git a/Lib.AspNetCore.ServerTiming/ServerTimingDeliveryMode.cs b/Lib.AspNetCore.ServerTiming.Abstractions/ServerTimingDeliveryMode.cs
similarity index 100%
rename from Lib.AspNetCore.ServerTiming/ServerTimingDeliveryMode.cs
rename to Lib.AspNetCore.ServerTiming.Abstractions/ServerTimingDeliveryMode.cs
diff --git a/Lib.AspNetCore.ServerTiming.sln b/Lib.AspNetCore.ServerTiming.sln
index 4ff2fa9..30da484 100644
--- a/Lib.AspNetCore.ServerTiming.sln
+++ b/Lib.AspNetCore.ServerTiming.sln
@@ -9,7 +9,7 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Test.AspNetCore.ServerTimin
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Demo.AspNetCore.ServerTiming", "Demo.AspNetCore.ServerTiming\Demo.AspNetCore.ServerTiming.csproj", "{C7A47113-CBA9-486C-8F95-50B2E12D71B3}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DocFx.AspNetCore.ServerTiming", "DocFx.AspNetCore.ServerTiming\DocFx.AspNetCore.ServerTiming.csproj", "{E7DC599F-40C9-4651-97B9-6B47CD05BA0D}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "DocFx.AspNetCore.ServerTiming", "DocFx.AspNetCore.ServerTiming\DocFx.AspNetCore.ServerTiming.csproj", "{E7DC599F-40C9-4651-97B9-6B47CD05BA0D}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{0AE38B1E-B1A7-4CB7-8F17-54AED3982407}"
 	ProjectSection(SolutionItems) = preProject
@@ -18,6 +18,8 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution
 		README.md = README.md
 	EndProjectSection
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lib.AspNetCore.ServerTiming.Abstractions", "Lib.AspNetCore.ServerTiming.Abstractions\Lib.AspNetCore.ServerTiming.Abstractions.csproj", "{B7DECE31-F8E4-4503-BF5B-1A8D5671F4FD}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -40,6 +42,10 @@ Global
 		{E7DC599F-40C9-4651-97B9-6B47CD05BA0D}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{E7DC599F-40C9-4651-97B9-6B47CD05BA0D}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{E7DC599F-40C9-4651-97B9-6B47CD05BA0D}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B7DECE31-F8E4-4503-BF5B-1A8D5671F4FD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B7DECE31-F8E4-4503-BF5B-1A8D5671F4FD}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B7DECE31-F8E4-4503-BF5B-1A8D5671F4FD}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B7DECE31-F8E4-4503-BF5B-1A8D5671F4FD}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
diff --git a/Lib.AspNetCore.ServerTiming/Filters/RestrictDescriptionsToDevelopmentMetricFilter.cs b/Lib.AspNetCore.ServerTiming/Filters/RestrictDescriptionsToDevelopmentMetricFilter.cs
index 26916e3..53d4716 100644
--- a/Lib.AspNetCore.ServerTiming/Filters/RestrictDescriptionsToDevelopmentMetricFilter.cs
+++ b/Lib.AspNetCore.ServerTiming/Filters/RestrictDescriptionsToDevelopmentMetricFilter.cs
@@ -36,7 +36,7 @@ public override bool OnServerTimingHeaderPreparation(HttpContext context, IColle
         {
             if (!IsDevelopment)
             {
-                List<ServerTimingMetric> newMetrics = metrics .Select(m => new ServerTimingMetric(m.Name,m.Value,null)).ToList();
+                List<ServerTimingMetric> newMetrics = metrics .Select(m => m.Value.HasValue ? new ServerTimingMetric(m.Name, m.Value.Value, null) : new ServerTimingMetric(m.Name, null)).ToList();
                 metrics.Clear();
                 newMetrics.ForEach(m => metrics.Add(m));
             }
diff --git a/Lib.AspNetCore.ServerTiming/Lib.AspNetCore.ServerTiming.csproj b/Lib.AspNetCore.ServerTiming/Lib.AspNetCore.ServerTiming.csproj
index 65e8986..aa7ff4a 100644
--- a/Lib.AspNetCore.ServerTiming/Lib.AspNetCore.ServerTiming.csproj
+++ b/Lib.AspNetCore.ServerTiming/Lib.AspNetCore.ServerTiming.csproj
@@ -25,6 +25,9 @@
   <ItemGroup>
     <None Include="..\README.md" Pack="true" PackagePath="\" />
   </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\Lib.AspNetCore.ServerTiming.Abstractions\Lib.AspNetCore.ServerTiming.Abstractions.csproj" />
+  </ItemGroup>
   <ItemGroup Condition="('$(TargetFramework)' == 'netcoreapp2.1') Or ('$(TargetFramework)' == 'net461')">
     <PackageReference Include="Microsoft.AspNetCore.Http" Version="[2.1.0,3.0.0)" />
     <PackageReference Include="Microsoft.AspNetCore.Hosting.Abstractions" Version="[2.1.0,3.0.0)" />
diff --git a/Lib.AspNetCore.ServerTiming/ServerTimingUtility.cs b/Lib.AspNetCore.ServerTiming/ServerTimingUtility.cs
index 3ab08c2..df875f4 100644
--- a/Lib.AspNetCore.ServerTiming/ServerTimingUtility.cs
+++ b/Lib.AspNetCore.ServerTiming/ServerTimingUtility.cs
@@ -145,8 +145,7 @@ internal static void SetServerTimingDeliveryMode(this IServerTiming serverTiming
         }
 
         // Format a metric name from caller params --> "{fileName}.{function}+{lineNumber}
-        private static string FormatCallerName(string functionName, string filePath, int lineNumber) =>
-            String.Concat(Path.GetFileNameWithoutExtension(filePath), ".", functionName, "+", lineNumber);
+        private static string FormatCallerName(string functionName, string filePath, int lineNumber) => String.Concat(Path.GetFileNameWithoutExtension(filePath), ".", functionName, "+", lineNumber);
 
         // On dispose, add server timing performance metric.
         private sealed class ServerTimingInstance : IDisposable
diff --git a/Test.AspNetCore.ServerTiming/Filters/IPRangeMetricFilterTests.cs b/Test.AspNetCore.ServerTiming/Filters/IPRangeMetricFilterTests.cs
index 7f93a09..434eeb8 100644
--- a/Test.AspNetCore.ServerTiming/Filters/IPRangeMetricFilterTests.cs
+++ b/Test.AspNetCore.ServerTiming/Filters/IPRangeMetricFilterTests.cs
@@ -1,8 +1,8 @@
 using System.Net;
 using System.Collections.Generic;
 using Microsoft.AspNetCore.Http;
-using Lib.AspNetCore.ServerTiming.Http.Headers;
 using Lib.AspNetCore.ServerTiming.Filters;
+using Lib.AspNetCore.ServerTiming.Http.Headers;
 using Xunit;
 
 
diff --git a/Test.AspNetCore.ServerTiming/Filters/RestrictDescriptionsToDevelopmentMetricFilterTests.cs b/Test.AspNetCore.ServerTiming/Filters/RestrictDescriptionsToDevelopmentMetricFilterTests.cs
index c6a6fb3..6c87625 100644
--- a/Test.AspNetCore.ServerTiming/Filters/RestrictDescriptionsToDevelopmentMetricFilterTests.cs
+++ b/Test.AspNetCore.ServerTiming/Filters/RestrictDescriptionsToDevelopmentMetricFilterTests.cs
@@ -1,7 +1,7 @@
 using System.Collections.Generic;
 using Microsoft.AspNetCore.Http;
-using Lib.AspNetCore.ServerTiming.Http.Headers;
 using Lib.AspNetCore.ServerTiming.Filters;
+using Lib.AspNetCore.ServerTiming.Http.Headers;
 using Moq;
 using Xunit;
 
diff --git a/Test.AspNetCore.ServerTiming/Filters/RestrictToDevelopmentMetricFilterTests.cs b/Test.AspNetCore.ServerTiming/Filters/RestrictToDevelopmentMetricFilterTests.cs
index 3693dff..d2cc56d 100644
--- a/Test.AspNetCore.ServerTiming/Filters/RestrictToDevelopmentMetricFilterTests.cs
+++ b/Test.AspNetCore.ServerTiming/Filters/RestrictToDevelopmentMetricFilterTests.cs
@@ -1,7 +1,7 @@
 using System.Collections.Generic;
 using Microsoft.AspNetCore.Http;
-using Lib.AspNetCore.ServerTiming.Http.Headers;
 using Lib.AspNetCore.ServerTiming.Filters;
+using Lib.AspNetCore.ServerTiming.Http.Headers;
 using Moq;
 using Xunit;