Option fold problem

fold.scala

scala> Some(1).map(_ :: Nil) getOrElse Nil
res0: List[Int] = List(1)

scala> Some(1).fold(Nil)(_ :: Nil)
<console>:8: error: type mismatch;
 found   : List[Int]
 required: scala.collection.immutable.Nil.type
              Some(1).fold(Nil)(_ :: Nil)
                                  ^

scala> Some(1).fold(Nil: List[Int])(_ :: Nil)
res2: List[Int] = List(1)