I am noticing something strange on elixir 1.9.4 with erlang 22.2.

Erlang/OTP 22 [erts-10.6] [source] [64-bit] [smp:1:1] [ds:1:1:10] [async-threads:1] [hipe]

Interactive Elixir (1.9.4) - press Ctrl+C to exit (type h() ENTER for help)
iex(app@127.0.0.1)1>  :ets.new(:test_table, [:set, :named_table, :public, {:write_concurrency, true}, {:read_concurrency, true}])  
:test_table
iex(app@127.0.0.1)2>  :ets.info(:test_table)
[
  id: #Reference<0.3021804751.1718747137.69759>,
  read_concurrency: true,
  write_concurrency: false,
  compressed: false,
  memory: 301,
  owner: #PID<0.2177.7>,
  heir: :none,
  name: :test_table,
  size: 0,
  node: :"app@127.0.0.1",
  named_table: true,
  type: :set,
  keypos: 1,
  protection: :public
]

It appears that the write_concurrency property is not being respected. Does anybody know if this is a regression?