Iex compile does not produce .beam file (1.5)

I’ve been away from Elixir for a while. In the past, having a module like this in file avg.ex

defmodule Avg do
  def avg(a,b) do
    (a + b) / 2.0

Then doing this in iex:

iex(1)> c("avg.ex")

would create a .beam file. It doesn’t seem to do so under version 1.5:

Erlang/OTP 19 [erts-8.2] [source] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false]

Interactive Elixir (1.5.0) - press Ctrl+C to exit (type h() ENTER for help)

What am I doing wrong?

Changelog of 1.4.0:

[IEx.Helpers] c/1 now compiles in memory by default to avoid common issue where .beam files remain at projects root directory