Select For Update in Elixir Transaction

I am trying to avoid deadlock between my Ecto Transaction operating on the same Table. To do that I am trying to replicate Postgres “Select .. for Update” in Ecto Multi.
Question is: Can I avoid lock here?

Query:

    query =
      from(s in Split,
        where: <condition>
        lock: fragment("FOR UPDATE OF ?", s),
        order_by: [asc: :id],
        select: %{
          id: s.id
        }
      )

    Repo.multi_update_all(
      multi,
      :updated_splits,
      from(s in Split,
        join: t in subquery(query),
        on: s.id == t.id,
        update: [
          set: [
            ....
          ]
        ]
       ),
      []
    )