diff --git a/backends/dockerclient.go b/backends/dockerclient.go
index a25350e7c4..f99dad27d0 100644
--- a/backends/dockerclient.go
+++ b/backends/dockerclient.go
@@ -45,7 +45,7 @@ func DockerClientWithConfig(config *DockerClientConfig) beam.Sender {
 			Server: beam.NewServer(),
 		}
 		b.Server.OnVerb(beam.Attach, beam.Handler(b.attach))
-		b.Server.OnVerb(beam.Start, beam.Handler(b.start))
+		b.Server.OnStart(b.start)
 		b.Server.OnLs(b.ls)
 		b.Server.OnSpawn(b.spawn)
 		return b.Server, nil
@@ -81,8 +81,7 @@ func (b *dockerClientBackend) attach(ctx *beam.Message) error {
 	return nil
 }
 
-func (b *dockerClientBackend) start(ctx *beam.Message) error {
-	ctx.Ret.Send(&beam.Message{Verb: beam.Ack})
+func (b *dockerClientBackend) start() error {
 	return nil
 }
 
@@ -133,8 +132,8 @@ func (b *dockerClientBackend) newContainer(id string) beam.Sender {
 	c := &container{backend: b, id: id}
 	instance := beam.NewServer()
 	instance.OnVerb(beam.Attach, beam.Handler(c.attach))
-	instance.OnVerb(beam.Start, beam.Handler(c.start))
-	instance.OnVerb(beam.Stop, beam.Handler(c.stop))
+	instance.OnStart(c.start)
+	instance.OnStop(c.stop)
 	instance.OnVerb(beam.Get, beam.Handler(c.get))
 	return instance
 }
@@ -160,7 +159,7 @@ func (c *container) attach(ctx *beam.Message) error {
 	return nil
 }
 
-func (c *container) start(ctx *beam.Message) error {
+func (c *container) start() error {
 	path := fmt.Sprintf("/containers/%s/start", c.id)
 	resp, err := c.backend.client.call("POST", path, "{}")
 	if err != nil {
@@ -173,13 +172,10 @@ func (c *container) start(ctx *beam.Message) error {
 	if resp.StatusCode != 204 {
 		return fmt.Errorf("expected status code 204, got %d:\n%s", resp.StatusCode, respBody)
 	}
-	if _, err := ctx.Ret.Send(&beam.Message{Verb: beam.Ack}); err != nil {
-		return err
-	}
 	return nil
 }
 
-func (c *container) stop(ctx *beam.Message) error {
+func (c *container) stop() error {
 	path := fmt.Sprintf("/containers/%s/stop", c.id)
 	resp, err := c.backend.client.call("POST", path, "")
 	if err != nil {
@@ -192,9 +188,6 @@ func (c *container) stop(ctx *beam.Message) error {
 	if resp.StatusCode != 204 {
 		return fmt.Errorf("expected status code 204, got %d:\n%s", resp.StatusCode, respBody)
 	}
-	if _, err := ctx.Ret.Send(&beam.Message{Verb: beam.Ack}); err != nil {
-		return err
-	}
 	return nil
 }
 
diff --git a/beam/server.go b/beam/server.go
index ecd4ebdaa6..b241edf6fe 100644
--- a/beam/server.go
+++ b/beam/server.go
@@ -49,6 +49,26 @@ func (s *Server) OnSpawn(h func(cmd ...string) (Sender, error)) *Server {
 	}))
 }
 
+func (s *Server) OnStart(h func() error) *Server {
+	return s.OnVerb(Start, Handler(func(msg *Message) error {
+		if err := h(); err != nil {
+			return err
+		}
+		_, err := msg.Ret.Send(&Message{Verb: Ack})
+		return err
+	}))
+}
+
+func (s *Server) OnStop(h func() error) *Server {
+	return s.OnVerb(Stop, Handler(func(msg *Message) error {
+		if err := h(); err != nil {
+			return err
+		}
+		_, err := msg.Ret.Send(&Message{Verb: Ack})
+		return err
+	}))
+}
+
 func (s *Server) Send(msg *Message) (Receiver, error) {
 	if h, exists := s.handlers[msg.Verb]; exists {
 		return h.Send(msg)