diff --git a/lib/elixir/test/elixir/protocol_test.exs b/lib/elixir/test/elixir/protocol_test.exs
index 8cb96d0eee4..9cff09661b3 100644
--- a/lib/elixir/test/elixir/protocol_test.exs
+++ b/lib/elixir/test/elixir/protocol_test.exs
@@ -3,10 +3,6 @@ Code.require_file("test_helper.exs", __DIR__)
 defmodule ProtocolTest do
   use ExUnit.Case, async: true
 
-  defp capture_err(fun) do
-    ExUnit.CaptureIO.capture_io(:stderr, fun)
-  end
-
   doctest Protocol
 
   {_, _, sample_binary, _} =