diff --git a/F4SDM42WebApi/F4SD - M42WebApi.csproj b/F4SDM42WebApi/F4SD - M42WebApi.csproj
index 340913d..40a3eca 100644
--- a/F4SDM42WebApi/F4SD - M42WebApi.csproj	
+++ b/F4SDM42WebApi/F4SD - M42WebApi.csproj	
@@ -13,7 +13,7 @@
     <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
     <M42ExtensionId>6673a25d-33d6-4072-91d9-abed4be1a966</M42ExtensionId>
     <M42AssemblyPattern>C4ITF4SD*.*</M42AssemblyPattern>
-    <M42PackageVersion>1.4.0.27</M42PackageVersion>
+    <M42PackageVersion>1.4.0.28</M42PackageVersion>
     <M42BuildPackage>true</M42BuildPackage>
   </PropertyGroup>
 
diff --git a/F4SDM42WebApi/F4SDM42WebApiController.cs b/F4SDM42WebApi/F4SDM42WebApiController.cs
index 9440a6f..148e42c 100644
--- a/F4SDM42WebApi/F4SDM42WebApiController.cs
+++ b/F4SDM42WebApi/F4SDM42WebApiController.cs
@@ -163,8 +163,12 @@ namespace C4IT.F4SD
                 .Invoke(null, null);
         }
 
-        private sealed class NoOpInterfaceProxy : DispatchProxy
+        public class NoOpInterfaceProxy : DispatchProxy
         {
+            public NoOpInterfaceProxy()
+            {
+            }
+
             protected override object Invoke(MethodInfo targetMethod, object[] args)
             {
                 return GetDefaultValue(targetMethod?.ReturnType);