When I try to call automated method with string constants, I had the compile-time error: 'Error: Type is not automatable: "WideString"'. What I do wrong? Or may be It's a bug?

----------- begin verror.pp ------------

{$mode objfpc}
program VError;
var
  v : variant;
  s : ansistring;
begin
 v.lalala(11);       // compiled
 v.blabla(s);        // compiled
 v.ololo('dummy');   // verror.pp(12,17) Error: Type is not
automatable: "WideString"
end.

----------- end verror.pp ------------