Setting `scrollTop` doesn't work initially

ScrollTest.elm

module ScrollTest exposing (..)

import Html.App as Html
import Html exposing (Html, Attribute, div, text, button)
import Html.Attributes exposing (style, property)
import Html.Events exposing (onClick)
import Json.Encode as Json
import String


main : Program Never
main =
    Html.beginnerProgram
        { model = model
        , view = view
        , update = update
        }



-- MODEL


type alias Model =
    Bool


model : Model
model =
    True



-- UPDATE


type Msg
    = Toggle


update : Msg -> Model -> Model
update msg model =
    case msg of
        Toggle ->
            not model



-- VIEW


view : Model -> Html Msg
view model =
    div []
        [ button [ onClick Toggle ] [ text "Toggle" ]
        , div (divStyle model)
            [ text aLotOfText ]
        , div [] [ text (toString model) ]
        ]


(=>) =
    (,)


divStyle : Bool -> List (Attribute msg)
divStyle scrolled =
    [ style
        [ "border" => "1px solid black"
        , "overflow" => "scroll"
        , "width" => "100px"
        , "height" => "100px"
        ]
    ]
        ++ if scrolled then
            [ property "scrollTop" (Json.int 100) ]
           else
            []


aLotOfText : String
aLotOfText =
    String.repeat 20 "A lot of text! "