diff --git a/.github/workflows/integration-tests.yml b/.github/workflows/integration-tests.yml
index 4096c16..8517e11 100644
--- a/.github/workflows/integration-tests.yml
+++ b/.github/workflows/integration-tests.yml
@@ -178,10 +178,10 @@ jobs:
       # ── Build and test ─────────────────────────────────────────────────
 
       - name: Build module
-        run: dotnet publish src/PSProxmoxVE/PSProxmoxVE.csproj --configuration Release --framework net9.0 --output ./publish/net9.0
+        run: dotnet publish src/PSProxmoxVE/PSProxmoxVE.csproj --configuration Release --framework netstandard2.0 --output ./publish/netstandard2.0
 
       - name: Clean publish output for PS module loading
-        run: rm -f ./publish/net9.0/*.deps.json ./publish/net9.0/*.runtimeconfig.json
+        run: rm -f ./publish/netstandard2.0/*.deps.json
 
       - name: Install Pester 5
         shell: pwsh
@@ -192,7 +192,7 @@ jobs:
         run: |
           $modulePath = "$HOME/.local/share/powershell/Modules/PSProxmoxVE"
           New-Item -ItemType Directory -Path $modulePath -Force | Out-Null
-          Copy-Item -Path ./publish/net9.0/* -Destination $modulePath -Recurse -Force
+          Copy-Item -Path ./publish/netstandard2.0/* -Destination $modulePath -Recurse -Force
 
       - name: Create test ISO
         shell: bash
@@ -201,8 +201,6 @@ jobs:
       - name: Run integration tests
         shell: pwsh
         env:
-          DOTNET_ROOT: ''
-          DOTNET_MULTILEVEL_LOOKUP: ''
           PVETEST_HOST: ${{ steps.target.outputs.host }}
           PVETEST_PORT: ${{ steps.target.outputs.port }}
           PVETEST_APITOKEN: ${{ steps.target.outputs.token }}
diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index d8406ba..4339bb1 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -18,9 +18,9 @@ jobs:
           - os: windows-latest
             framework: net48
           - os: windows-latest
-            framework: net9.0
+            framework: netstandard2.0
           - os: ubuntu-latest
-            framework: net9.0
+            framework: netstandard2.0
 
     steps:
       - uses: actions/checkout@v5
@@ -58,17 +58,17 @@ jobs:
             shell: powershell
           - os: windows-latest
             ps_version: '7.5'
-            framework: net9.0
+            framework: netstandard2.0
             artifact_os: windows-latest
             shell: pwsh
           - os: ubuntu-latest
             ps_version: '7.5'
-            framework: net9.0
+            framework: netstandard2.0
             artifact_os: ubuntu-latest
             shell: pwsh
           - os: macos-latest
             ps_version: '7.5'
-            framework: net9.0
+            framework: netstandard2.0
             artifact_os: ubuntu-latest
             shell: pwsh
 
diff --git a/src/PSProxmoxVE.Core/Client/PveHttpClient.cs b/src/PSProxmoxVE.Core/Client/PveHttpClient.cs
index 721eca2..02c1600 100644
--- a/src/PSProxmoxVE.Core/Client/PveHttpClient.cs
+++ b/src/PSProxmoxVE.Core/Client/PveHttpClient.cs
@@ -10,7 +10,7 @@ using Newtonsoft.Json.Linq;
 using PSProxmoxVE.Core.Authentication;
 using PSProxmoxVE.Core.Exceptions;
 
-#if NET48
+#if NET48 || NETSTANDARD2_0
 using System.Net.Security;
 using System.Security.Cryptography.X509Certificates;
 #endif
@@ -35,7 +35,7 @@ namespace PSProxmoxVE.Core.Client
             _session = session ?? throw new ArgumentNullException(nameof(session));
             _baseUrl = session.BaseUrl;
 
-#if NET48
+#if NET48 || NETSTANDARD2_0
             var handler = new HttpClientHandler();
             if (session.SkipCertificateCheck)
             {
@@ -75,7 +75,7 @@ namespace PSProxmoxVE.Core.Client
             _session = null;
             _baseUrl = $"https://{hostname}:{port}";
 
-#if NET48
+#if NET48 || NETSTANDARD2_0
             var handler = new HttpClientHandler();
             if (skipCertificateCheck)
             {
@@ -286,7 +286,7 @@ namespace PSProxmoxVE.Core.Client
             }
             finally
             {
-#if NET48
+#if NET48 || NETSTANDARD2_0
                 fileStream.Dispose();
 #else
                 await fileStream.DisposeAsync().ConfigureAwait(false);
diff --git a/src/PSProxmoxVE.Core/PSProxmoxVE.Core.csproj b/src/PSProxmoxVE.Core/PSProxmoxVE.Core.csproj
index f00c7d2..5b444e8 100644
--- a/src/PSProxmoxVE.Core/PSProxmoxVE.Core.csproj
+++ b/src/PSProxmoxVE.Core/PSProxmoxVE.Core.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net9.0;net48</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;net9.0;net48</TargetFrameworks>
     <LangVersion>10.0</LangVersion>
     <Nullable>enable</Nullable>
     <RootNamespace>PSProxmoxVE.Core</RootNamespace>
@@ -16,6 +16,11 @@
     </AssemblyAttribute>
   </ItemGroup>
 
+  <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
+    <PackageReference Include="System.Text.Json" Version="8.0.5" />
+  </ItemGroup>
+
   <ItemGroup Condition="'$(TargetFramework)' == 'net48'">
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
     <PackageReference Include="System.Text.Json" Version="8.0.5" />
diff --git a/src/PSProxmoxVE/PSProxmoxVE.csproj b/src/PSProxmoxVE/PSProxmoxVE.csproj
index 8baa638..f1ce353 100644
--- a/src/PSProxmoxVE/PSProxmoxVE.csproj
+++ b/src/PSProxmoxVE/PSProxmoxVE.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net9.0;net48</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;net9.0;net48</TargetFrameworks>
     <LangVersion>10.0</LangVersion>
     <Nullable>enable</Nullable>
     <RootNamespace>PSProxmoxVE</RootNamespace>
@@ -14,7 +14,7 @@
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetFramework)' == 'net48'">
+  <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0' Or '$(TargetFramework)' == 'net48'">
     <PackageReference Include="PowerShellStandard.Library" Version="5.1.1" PrivateAssets="all" />
   </ItemGroup>
 
diff --git a/tests/PSProxmoxVE.Tests/_TestHelper.ps1 b/tests/PSProxmoxVE.Tests/_TestHelper.ps1
index 57cc926..af43701 100644
--- a/tests/PSProxmoxVE.Tests/_TestHelper.ps1
+++ b/tests/PSProxmoxVE.Tests/_TestHelper.ps1
@@ -30,10 +30,10 @@ $repoRoot = Resolve-Path (Join-Path $PSScriptRoot '../..')
 $moduleRoot = Join-Path $repoRoot 'src/PSProxmoxVE'
 
 if ($PSVersionTable.PSEdition -eq 'Core') {
-    $frameworks = @('net9.0', 'net48')
+    $frameworks = @('netstandard2.0', 'net9.0', 'net48')
 }
 else {
-    $frameworks = @('net48', 'net9.0')
+    $frameworks = @('net48', 'netstandard2.0', 'net9.0')
 }
 
 $searchPaths = foreach ($fw in $frameworks) {