[Lazarus] Why doesn't this work?

[Erwin van den Bosch]

procedure TForm1.Button1Click(Sender: TObject);
var
   iLastError: integer;
begin
   iLastError:=10053;
   if iLastError in [10053, 10054] then Label1.Caption:='Yes, it works!'
                                   else Label1.Caption:='No, it doesn''t 
work!';
   // Output : No, it doesn''t work!
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
   iLastError:=53;
   if iLastError in [53, 54] then Label1.Caption:='Yes, it works!'
                             else Label1.Caption:='No, it doesn''t work!';
   // Output : Yes, it works!
end;

Is there A compiler directive for testing on big nummers?

(fpc:2.6.1 Lazarus: 1.0.3 i386 on Windows 7 x64)

-- 
    Erwin