diff --git a/components/virtualtreeview-unstable/VirtualTrees.pas b/components/virtualtreeview-unstable/VirtualTrees.pas
index 617c97b6e..e117b686f 100644
--- a/components/virtualtreeview-unstable/VirtualTrees.pas
+++ b/components/virtualtreeview-unstable/VirtualTrees.pas
@@ -790,7 +790,7 @@ type
     function GetData(const FormatEtcIn: TFormatEtc; out Medium: TStgMedium): HResult; virtual; stdcall;
     function GetDataHere(const FormatEtc: TFormatEtc; out Medium: TStgMedium): HResult; virtual; stdcall;
     function QueryGetData(const FormatEtc: TFormatEtc): HResult; virtual; stdcall;
-    function SetData(const FormatEtc: TFormatEtc; var Medium: TStgMedium; DoRelease: BOOL): HResult; virtual; stdcall;
+    function SetData(const FormatEtc: TFormatEtc; {$ifdef VER2_0}var{$else}const{$endif} Medium: TStgMedium; DoRelease: BOOL): HResult; virtual; stdcall;
   end;
 
   // TVTDragManager is a class to manage drag and drop in a Virtual Treeview.
@@ -6244,7 +6244,7 @@ end;
 
 //----------------------------------------------------------------------------------------------------------------------
 
-function TVTDataObject.SetData(const FormatEtc: TFormatEtc; var Medium: TStgMedium; DoRelease: BOOL): HResult;
+function TVTDataObject.SetData(const FormatEtc: TFormatEtc; {$ifdef VER2_0}var{$else}const{$endif} Medium: TStgMedium; DoRelease: BOOL): HResult;
 
 // Allows dynamic adding to the IDataObject during its existance. Most noteably it is used to implement
 // IDropSourceHelper and allows to set a special format for optimized moves during a shell transfer.