I am on XE6, the following statement should include JSon, and NOT DBXJSon. But for some reason, it does not work. What am i doing wrong?

I am on XE6, the following statement should include JSon, and NOT DBXJSon. But for some reason, it does not work. What am i doing wrong?

interface

{$if CompilerVersion >= 27)
  {$Define DelphiXe6_Up}
{$EndIf}

uses
  {$IfDef DelphiXe6_Up }
  JSon;
  {$Else}
  DBXJSon;
  {$EndIf}