"is" and "as" operators cross-compile incorrectly when using class member variables

private var classDef:Class = String;
public function test1(param:Object):Object
{
	if (param is this.classDef)
		return param as this.classDef;
	return null;
}

WeaveTest.prototype.classDef;
WeaveTest.prototype.test1 = function(param) {
  if (org.apache.flex.utils.Language.is(param, classDef))
    return org.apache.flex.utils.Language.as(param, classDef);
  return null;
};