How to change TScrollBox horizonal scrollbar size (width or height) in Delphi under Windows 10?

Question

I want to change the TScrollBox scrollbar size - I was using this:

Uses
  CommCtrl;
....
  InitializeFlatSB(Scrollbox1.handle);
  FlatSB_SetScrollProp(Scrollbox1.Handle, WSB_PROP_CXVSCROLL, 10, true);

...but I think that it's not working anymore with Windows 10.