diff --git a/.github/workflows/cd-aspnet-extensions.yml b/.github/workflows/cd-aspnet-extensions.yml
index f688742..fa3237c 100644
--- a/.github/workflows/cd-aspnet-extensions.yml
+++ b/.github/workflows/cd-aspnet-extensions.yml
@@ -28,6 +28,10 @@ jobs:
       uses: actions/setup-dotnet@v4
       with:
         dotnet-version: '8.0.x'
+    - name: Setup .NET 9.0 SDK
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: '9.0.x'
     - name: Restore
       run: dotnet restore
     - name: Build
diff --git a/.github/workflows/cd-azure-functions-worker-extensions.yml b/.github/workflows/cd-azure-functions-worker-extensions.yml
index 69a9358..2f6a488 100644
--- a/.github/workflows/cd-azure-functions-worker-extensions.yml
+++ b/.github/workflows/cd-azure-functions-worker-extensions.yml
@@ -28,6 +28,10 @@ jobs:
       uses: actions/setup-dotnet@v4
       with:
         dotnet-version: '8.0.x'
+    - name: Setup .NET 9.0 SDK
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: '9.0.x'
     - name: Restore
       run: dotnet restore
     - name: Build
diff --git a/.github/workflows/cd-azure-webjobs-extensions.yml b/.github/workflows/cd-azure-webjobs-extensions.yml
index 99fe7ee..d1cc86c 100644
--- a/.github/workflows/cd-azure-webjobs-extensions.yml
+++ b/.github/workflows/cd-azure-webjobs-extensions.yml
@@ -28,6 +28,10 @@ jobs:
       uses: actions/setup-dotnet@v4
       with:
         dotnet-version: '8.0.x'
+    - name: Setup .NET 9.0 SDK
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: '9.0.x'
     - name: Restore
       run: dotnet restore
     - name: Build
diff --git a/.github/workflows/cd-net-http.yml b/.github/workflows/cd-net-http.yml
index 372ee92..de13b79 100644
--- a/.github/workflows/cd-net-http.yml
+++ b/.github/workflows/cd-net-http.yml
@@ -28,6 +28,10 @@ jobs:
       uses: actions/setup-dotnet@v4
       with:
         dotnet-version: '8.0.x'
+    - name: Setup .NET 9.0 SDK
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: '9.0.x'
     - name: Restore
       run: dotnet restore
     - name: Build
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 16fd352..a2870d5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -28,6 +28,10 @@ jobs:
       uses: actions/setup-dotnet@v4
       with:
         dotnet-version: '8.0.x'
+    - name: Setup .NET 9.0 SDK
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: '9.0.x'
     - name: Restore
       run: dotnet restore
     - name: Build
diff --git a/.github/workflows/gh-pages.yml b/.github/workflows/gh-pages.yml
index d306305..54cb5b9 100644
--- a/.github/workflows/gh-pages.yml
+++ b/.github/workflows/gh-pages.yml
@@ -22,6 +22,10 @@ jobs:
       uses: actions/setup-dotnet@v4
       with:
         dotnet-version: '8.0.x'
+    - name: Setup .NET 9.0 SDK
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: '9.0.x'
     - name: Restore
       run: dotnet restore
     - name: Build
diff --git a/src/Lib.Net.Http.WebPush/Lib.Net.Http.WebPush.csproj b/src/Lib.Net.Http.WebPush/Lib.Net.Http.WebPush.csproj
index 112d471..325dd2f 100644
--- a/src/Lib.Net.Http.WebPush/Lib.Net.Http.WebPush.csproj
+++ b/src/Lib.Net.Http.WebPush/Lib.Net.Http.WebPush.csproj
@@ -34,7 +34,7 @@
     <PackageReference Include="Portable.BouncyCastle" Version="1.8.1.3" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="Lib.Net.Http.EncryptedContentEncoding" Version="2.1.0" />
+    <PackageReference Include="Lib.Net.Http.EncryptedContentEncoding" Version="2.1.1" />
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="DotNet.ReproducibleBuilds" Version="1.1.1" PrivateAssets="All" />
diff --git a/test/Test.Lib.Net.Http.WebPush/Test.Lib.Net.Http.WebPush.csproj b/test/Test.Lib.Net.Http.WebPush/Test.Lib.Net.Http.WebPush.csproj
index a445f57..26398af 100644
--- a/test/Test.Lib.Net.Http.WebPush/Test.Lib.Net.Http.WebPush.csproj
+++ b/test/Test.Lib.Net.Http.WebPush/Test.Lib.Net.Http.WebPush.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp3.1;net5.0;net6.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>netcoreapp3.1;net8.0;net9.0</TargetFrameworks>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
   <ItemGroup>
@@ -14,15 +14,12 @@
   <ItemGroup Condition="'$(TargetFramework)' == 'netcoreapp3.1'">
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="3.1.0" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetFramework)' == 'net5.0'">
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="5.0.0" />
-  </ItemGroup>
-  <ItemGroup Condition="'$(TargetFramework)' == 'net6.0'">
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="6.0.0" />
-  </ItemGroup>
   <ItemGroup Condition="'$(TargetFramework)' == 'net8.0'">
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="8.0.0" />
   </ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)' == 'net9.0'">
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="9.0.0" />
+  </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\src\Lib.Net.Http.WebPush\Lib.Net.Http.WebPush.csproj" />
   </ItemGroup>