diff --git a/lib/chronoscope/nts.ex b/lib/chronoscope/nts.ex
index 8e8c013..e370c18 100644
--- a/lib/chronoscope/nts.ex
+++ b/lib/chronoscope/nts.ex
@@ -44,9 +44,14 @@ defmodule Chronoscope.NTS do
 
     case Registry.lookup(NTS.Registry, name) do
       [{pid, _}] ->
-        pid
-        |> GenServer.call(:terminate)
-        |> wait_for_termination()
+        if Process.alive?(pid) do
+          pid
+          |> GenServer.call(:terminate)
+          |> wait_for_termination()
+        else
+          # Registry.unregister(NTS.Registry, name)
+          {:error, :notfound}
+        end
 
       [] ->
         {:error, :notfound}
@@ -55,20 +60,29 @@ defmodule Chronoscope.NTS do
 
   @impl true
   def key_establishment(host, port) do
-    GenServer.call(client_pid(host, port), :key_establishment)
+    GenServer.call(client_pid(%{host: host, port: port}), :key_establishment)
   end
 
-  defp client_pid(host, port) do
-    name = "#{host}:#{port}"
+  defp client_pid(server) do
+    name = "#{server.host}:#{server.port}"
 
     case Registry.lookup(NTS.Registry, name) do
       [{pid, _}] ->
-        pid
+        if Process.alive?(pid) do
+          pid
+        else
+          # Registry.unregister(NTS.Registry, name)
+          start_client(server, name)
+        end
 
       [] ->
-        NTS.DynamicSupervisor
-        |> DynamicSupervisor.start_child({NTS.Client, host: host, port: port, name: {:via, Registry, {NTS.Registry, name}}})
-        |> then(fn {:ok, pid} -> pid end)
+        start_client(server, name)
     end
   end
+
+  defp start_client(%{host: host, port: port}, name) do
+    NTS.DynamicSupervisor
+    |> DynamicSupervisor.start_child({NTS.Client, host: host, port: port, name: {:via, Registry, {NTS.Registry, name}}})
+    |> then(fn {:ok, pid} -> pid end)
+  end
 end
diff --git a/test/chronoscope/nts/client_test.exs b/test/chronoscope/nts/client_test.exs
index e05340e..55a6e00 100644
--- a/test/chronoscope/nts/client_test.exs
+++ b/test/chronoscope/nts/client_test.exs
@@ -31,6 +31,10 @@ defmodule Chronoscope.NTS.ClientTest do
   end
 
   describe "Chronoscope.NTS.Client.handle_call()" do
+    test ":terminate" do
+      assert handle_call(:terminate, nil, %{state: true}) == {:stop, :normal, self(), %{state: true}}
+    end
+
     test ":list" do
       assert handle_call(:list, nil, %{state: true}) == {:reply, %{state: true}, %{state: true}}
     end
diff --git a/test/chronoscope/nts_test.exs b/test/chronoscope/nts_test.exs
index 9614077..48f283e 100644
--- a/test/chronoscope/nts_test.exs
+++ b/test/chronoscope/nts_test.exs
@@ -59,6 +59,31 @@ defmodule Chronoscope.NTSTest do
       assert remove("localhost", 1111) == {:error, :notfound}
       assert [%{host: "localhost", key_establishment_response: _, last_key_establishment: _, port: 4444}] = list()
     end
+
+    test "remove several clients" do
+      expect_key_establishment("localhost", 4444)
+      expect_key_establishment("localhost", 2222)
+      expect_key_establishment("localhost", 4444)
+      expect_key_establishment("localhost", 4444)
+      expect_key_establishment("localhost", 4444)
+      expect_key_establishment("localhost", 5555)
+
+      key_establishment("localhost", 4444)
+      key_establishment("localhost", 2222)
+      remove("localhost", 4444)
+      key_establishment("localhost", 4444)
+      remove("localhost", 4444)
+      key_establishment("localhost", 4444)
+      key_establishment("localhost", 4444)
+      remove("localhost", 4444)
+      remove("localhost", 4444)
+      key_establishment("localhost", 4444)
+      remove("localhost", 4444)
+      key_establishment("localhost", 5555)
+      remove("localhost", 5555)
+      remove("localhost", 2222)
+      assert list() == []
+    end
   end
 
   describe "Chronoscope.NTS.key_establishment()" do
diff --git a/test/support/ssl.ex b/test/support/ssl.ex
deleted file mode 100644
index e69de29..0000000