diff --git a/tutorial/delphi/DelphiServer/DelphiServer.dpr b/tutorial/delphi/DelphiServer/DelphiServer.dpr
index 5f2dc45..6b8e115 100644
--- a/tutorial/delphi/DelphiServer/DelphiServer.dpr
+++ b/tutorial/delphi/DelphiServer/DelphiServer.dpr
@@ -41,7 +41,7 @@
 
 
 type
-  TCalculatorHandler = class( TInterfacedObject, TCalculator.Iface)
+  TCalculatorHandler = class( TInterfacedObject, TSharedService.Iface, TCalculator.Iface)
   protected
     FLog : TDictionary< Integer, ISharedStruct>;