diff --git a/exercises/behaviours/server/lib/frequency.ex b/exercises/behaviours/server/lib/frequency.ex
index d73ba29..577441b 100644
--- a/exercises/behaviours/server/lib/frequency.ex
+++ b/exercises/behaviours/server/lib/frequency.ex
@@ -5,6 +5,7 @@ defmodule Frequency do
 
   ## API Calls (calling from Client process)
   def start(), do: Server.start(__MODULE__, [])
+  def stop(), do: Server.stop(__MODULE__)
   def allocate(), do: Server.call(__MODULE__, {:allocate, self()})
   def deallocate(freq), do: Server.call(__MODULE__, {:deallocate, freq})
 
diff --git a/exercises/behaviours/server/mix.lock b/exercises/behaviours/server/mix.lock
new file mode 100644
index 0000000..44ce6d8
--- /dev/null
+++ b/exercises/behaviours/server/mix.lock
@@ -0,0 +1,5 @@
+%{
+  "recon": {:hex, :recon, "2.5.0", "2f7fcbec2c35034bade2f9717f77059dc54eb4e929a3049ca7ba6775c0bd66cd", [:mix, :rebar3], [], "hexpm", "72f3840fedd94f06315c523f6cecf5b4827233bed7ae3fe135b2a0ebeab5e196"},
+  "redbug": {:hex, :redbug, "1.2.1", "9153ee50e42c39ce3f6efa65ee746f4a52896da66862cfb59e7c0f838b7b8414", [:rebar3], [], "hexpm", "bfc7bcb8743c55dbe0134dbcb89dd6a57606288cc4e2570eccd701061fbcbd93"},
+  "rexbug": {:hex, :rexbug, "1.0.4", "b9908d95da835c7353ef051bc587662c9054fa3c0c11e96de9bad7fe18460aad", [:mix], [{:mix_test_watch, ">= 0.5.0", [hex: :mix_test_watch, repo: "hexpm", optional: true]}, {:redbug, "~> 1.2", [hex: :redbug, repo: "hexpm", optional: false]}], "hexpm", "4826565f39e617fa0eea3e916f02928b2f1d880bf5e084cb80da86a3e369390e"},
+}
diff --git a/exercises/behaviours/server/test/frequencies_test.exs b/exercises/behaviours/server/test/frequencies_test.exs
new file mode 100644
index 0000000..6890831
--- /dev/null
+++ b/exercises/behaviours/server/test/frequencies_test.exs
@@ -0,0 +1,46 @@
+defmodule FrequencyTest do
+  use ExUnit.Case
+
+  ## WARNING: Don't make those kind of tests at home!
+
+  describe "Frequency tests" do
+    test "Test allocation" do
+      Frequency.start()
+      for i <- 10..15 do
+        assert {:ok, i} == Frequency.allocate()
+      end
+      assert {:error, _} = Frequency.allocate()
+      assert :stop = Frequency.stop()
+      :ok
+    end
+
+    test "Test deallocation" do
+      Frequency.start()
+      for i <- 1..5 do
+        assert :ok == Frequency.deallocate(i)
+      end
+      for i <- 5..1 do
+        assert {:ok, i} == Frequency.allocate()
+      end
+      assert {:ok, 10} = Frequency.allocate()
+      assert :stop = Frequency.stop()
+      :ok
+    end
+
+    test "List available frequencies" do
+      Frequency.start()
+      assert [10, 11, 12, 13, 14, 15] == Frequency.list_available()
+      assert :stop = Frequency.stop()
+      :ok
+    end
+
+    test "List allocated frequencies" do
+      Frequency.start()
+      assert [] == Frequency.list_allocated()
+      assert {:ok, 10} = Frequency.allocate()
+      assert [{10, _pid}] = Frequency.list_allocated()
+      assert :stop = Frequency.stop()
+      :ok
+    end
+  end
+end
diff --git a/exercises/behaviours/server/test/server_test.exs b/exercises/behaviours/server/test/server_test.exs
index 4fa9b61..6723ea7 100644
--- a/exercises/behaviours/server/test/server_test.exs
+++ b/exercises/behaviours/server/test/server_test.exs
@@ -1,8 +1,3 @@
 defmodule ServerTest do
   use ExUnit.Case
-  doctest Server
-
-  test "greets the world" do
-    assert Server.hello() == :world
-  end
 end