diff --git a/F4SDM42WebApi/F4SD - M42WebApi.csproj b/F4SDM42WebApi/F4SD - M42WebApi.csproj
index 2375f25..546cfef 100644
--- a/F4SDM42WebApi/F4SD - M42WebApi.csproj	
+++ b/F4SDM42WebApi/F4SD - M42WebApi.csproj	
@@ -13,7 +13,6 @@
     <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
     <M42ExtensionId>6673a25d-33d6-4072-91d9-abed4be1a966</M42ExtensionId>
     <M42AssemblyPattern>C4ITF4SD*.*</M42AssemblyPattern>
-    <M42PackageVersion>1.4.0.39</M42PackageVersion>
     <M42BuildPackage>true</M42BuildPackage>
   </PropertyGroup>
 
diff --git a/F4SDM42WebApi/M42SandboxedExtension.targets b/F4SDM42WebApi/M42SandboxedExtension.targets
index c7ca7e1..4d1bc7d 100644
--- a/F4SDM42WebApi/M42SandboxedExtension.targets
+++ b/F4SDM42WebApi/M42SandboxedExtension.targets
@@ -78,13 +78,22 @@
   <Target Name="M42_BuildPackage"
           AfterTargets="Build"
           Condition="'$(RuntimeIdentifier)' == '' AND '$(M42BuildPackage)' == 'true'">
-    <Error Condition="'$(M42PackageVersion)' == ''"
-           Text="M42PackageVersion is required when M42BuildPackage=true." />
     <Error Condition="!Exists('$(M42PackageTemplateDir)\package.json')"
            Text="M42 package template not found: $(M42PackageTemplateDir)" />
     <Error Condition="!Exists('$(M42BasePackageAssembliesDir)\C4ITF4SDM42WebApi.dll')"
            Text="M42 base package assemblies are missing: $(M42BasePackageAssembliesDir)" />
 
-    <Exec Command="powershell.exe -NoProfile -ExecutionPolicy Bypass -File &quot;$(M42PackageBuildScript)&quot; -TemplateDir &quot;$(M42PackageTemplateDir)&quot; -AssembliesDir &quot;$(M42BasePackageAssembliesDir)&quot; -OutputRoot &quot;$(M42PackageOutputRoot)&quot; -PackageName &quot;$(M42PackageName)&quot; -PackageVersion &quot;$(M42PackageVersion)&quot;" />
+    <GetAssemblyIdentity AssemblyFiles="$(M42BasePackageAssembliesDir)\C4ITF4SDM42WebApi.dll">
+      <Output TaskParameter="Assemblies" ItemName="_M42PackageAssemblyIdentity" />
+    </GetAssemblyIdentity>
+
+    <PropertyGroup>
+      <_M42PackageAssemblyVersion>@(_M42PackageAssemblyIdentity->'%(Version)')</_M42PackageAssemblyVersion>
+    </PropertyGroup>
+
+    <Error Condition="'$(_M42PackageAssemblyVersion)' == ''"
+           Text="Could not read AssemblyVersion from $(M42BasePackageAssembliesDir)\C4ITF4SDM42WebApi.dll." />
+
+    <Exec Command="powershell.exe -NoProfile -ExecutionPolicy Bypass -File &quot;$(M42PackageBuildScript)&quot; -TemplateDir &quot;$(M42PackageTemplateDir)&quot; -AssembliesDir &quot;$(M42BasePackageAssembliesDir)&quot; -OutputRoot &quot;$(M42PackageOutputRoot)&quot; -PackageName &quot;$(M42PackageName)&quot; -PackageVersion &quot;$(_M42PackageAssemblyVersion)&quot;" />
   </Target>
 </Project>
diff --git a/SharedAssemblyInfo.cs b/SharedAssemblyInfo.cs
index 6dbd71a..f42440a 100644
--- a/SharedAssemblyInfo.cs
+++ b/SharedAssemblyInfo.cs
@@ -5,5 +5,5 @@
 [assembly: AssemblyCopyright("Copyright © 2026, Consulting4IT GmbH, Germany")]
 [assembly: AssemblyTrademark("")]
 
-[assembly: AssemblyVersion("1.3.0.0")]
-[assembly: AssemblyInformationalVersion("1.3.0.0")]
\ No newline at end of file
+[assembly: AssemblyVersion("1.4.0.0")]
+[assembly: AssemblyInformationalVersion("1.4.0.0")]
diff --git a/docs/matrix42-26-1-extension-migration.md b/docs/matrix42-26-1-extension-migration.md
index a32a941..e0f0dce 100644
--- a/docs/matrix42-26-1-extension-migration.md
+++ b/docs/matrix42-26-1-extension-migration.md
@@ -26,11 +26,12 @@ Bewaehrte Projekt-Eigenschaften:
 <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
 <M42ExtensionId>...</M42ExtensionId>
 <M42AssemblyPattern>C4ITF4SD*.*</M42AssemblyPattern>
-<M42PackageVersion>...</M42PackageVersion>
 <M42BuildPackage>true</M42BuildPackage>
 ```
 
-Das Package wird ueber `M42SandboxedExtension.targets` gebaut. Ein erfolgreicher Release-Build erzeugt:
+Das Package wird ueber `M42SandboxedExtension.targets` gebaut. Die Paketversion wird automatisch aus der `AssemblyVersion` der gebauten WebApi-Assembly gelesen. In diesem Repo wird diese zentral in `SharedAssemblyInfo.cs` gepflegt.
+
+Ein erfolgreicher Release-Build erzeugt:
 
 ```text
 artifacts/<PackageName> v<Version>/