diff --git a/lib/elixir/lib/kernel/cli.ex b/lib/elixir/lib/kernel/cli.ex
index 4bcb9d94b8..0978d504de 100644
--- a/lib/elixir/lib/kernel/cli.ex
+++ b/lib/elixir/lib/kernel/cli.ex
@@ -56,7 +56,8 @@ defmodule Kernel.CLI do
   ## Private
 
   defp at_exit(status) do
-    hooks = :gen_server.call(:elixir_code_server, :at_exit)
+    hooks = :gen_server.call(:elixir_code_server, :flush_at_exit)
+
     lc hook inlist hooks do
       try do
         hook.(status)
@@ -72,6 +73,10 @@ defmodule Kernel.CLI do
           IO.puts Exception.formatted_stacktrace(trace)
       end
     end
+
+    # If an at_exit callback adds a
+    # new hook we need to invoke it.
+    unless hooks == [], do: at_exit(status)
   end
 
   defp invalid_option(option) do
diff --git a/lib/elixir/src/elixir_code_server.erl b/lib/elixir/src/elixir_code_server.erl
index ff7f626d12..10b90233d8 100644
--- a/lib/elixir/src/elixir_code_server.erl
+++ b/lib/elixir/src/elixir_code_server.erl
@@ -47,6 +47,9 @@ handle_call(loaded, _From, Config) ->
 handle_call(at_exit, _From, Config) ->
   { reply, Config#elixir_code_server.at_exit, Config };
 
+handle_call(flush_at_exit, _From, Config) ->
+  { reply, Config#elixir_code_server.at_exit, Config#elixir_code_server{at_exit=[]} };
+
 handle_call(argv, _From, Config) ->
   { reply, Config#elixir_code_server.argv, Config };
 
diff --git a/lib/ex_unit/lib/ex_unit.ex b/lib/ex_unit/lib/ex_unit.ex
index 6654afb2f9..27fb7b876d 100644
--- a/lib/ex_unit/lib/ex_unit.ex
+++ b/lib/ex_unit/lib/ex_unit.ex
@@ -65,11 +65,14 @@ defmodule ExUnit do
     options = Keyword.merge(user_options, options)    
     ExUnit.Server.start_link
     configure(options)
-    System.at_exit fn status ->
-      if status == 0 do
+    System.at_exit fn
+      0 ->
         failures = ExUnit.run
-        if failures > 0, do: System.halt(1), else: System.halt(0)
-      end
+        System.at_exit fn _ ->
+          if failures > 0, do: System.halt(1), else: System.halt(0)
+        end
+      _ ->
+        :ok
     end
   end