diff --git a/server/service.go b/server/service.go
index ec46cb2..48f51f1 100644
--- a/server/service.go
+++ b/server/service.go
@@ -39,6 +39,9 @@ type Service struct {
 	upgrader websocket.Upgrader
 	conns    map[string]*wsConn // Connections by wsConn Id's
 	wg       sync.WaitGroup     // Wait for all connections to be disconnected
+
+	// handlers for testing
+	onWSClose func(*websocket.Conn)
 }
 
 // NewService creates a new Service
@@ -75,6 +78,20 @@ func (s *Service) SetLogger(l logger.Logger) *Service {
 	return s
 }
 
+// SetOnWSClose sets a callback to be calld when a websocket connection is
+// closed. Used for testing.
+func (s *Service) SetOnWSClose(cb func(ws *websocket.Conn)) *Service {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if s.stop != nil {
+		panic("SetOnWSClose must be called before starting server")
+	}
+
+	s.onWSClose = cb
+	return s
+}
+
 // Logf writes a formatted log message
 func (s *Service) Logf(format string, v ...interface{}) {
 	s.logger.Log(fmt.Sprintf(format, v...))
diff --git a/server/wsHandler.go b/server/wsHandler.go
index 2f4a148..7e2c594 100644
--- a/server/wsHandler.go
+++ b/server/wsHandler.go
@@ -93,6 +93,10 @@ func (s *Service) wsHandler(w http.ResponseWriter, r *http.Request) {
 	if s.metrics != nil {
 		s.metrics.WSConnections.Add(-1)
 	}
+
+	if s.onWSClose != nil {
+		s.onWSClose(ws)
+	}
 }
 
 // wsHeaderAuth sends an auth resource request if WSHeaderAuth is set, and
diff --git a/test/test.go b/test/test.go
index 7f60273..e543c60 100644
--- a/test/test.go
+++ b/test/test.go
@@ -29,6 +29,7 @@ type Session struct {
 	*NATSTestClient
 	s     *server.Service
 	conns map[*Conn]struct{}
+	dcCh  chan struct{}
 	*CountLogger
 }
 
@@ -50,6 +51,15 @@ func setup(t *testing.T, cfgs ...func(*server.Config)) *Session {
 		CountLogger:    l,
 	}
 
+	// Set on WS close handler to synchronize tests with WebSocket disconnects.
+	serv.SetOnWSClose(func(_ *websocket.Conn) {
+		ch := s.dcCh
+		s.dcCh = nil
+		if ch != nil {
+			close(ch)
+		}
+	})
+
 	if err := serv.Start(); err != nil {
 		panic("test: failed to start server: " + err.Error())
 	}
diff --git a/test/ws.go b/test/ws.go
index 349237e..f6e8110 100644
--- a/test/ws.go
+++ b/test/ws.go
@@ -115,8 +115,24 @@ func (c *Conn) Request(method string, params interface{}) *ClientRequest {
 
 // Disconnect closes the connection to the gateway
 func (c *Conn) Disconnect() {
+	var dcCh chan struct{}
+	if c.s.dcCh == nil {
+		dcCh = make(chan struct{})
+		c.s.dcCh = dcCh
+	}
+
 	c.ws.Close()
 	<-c.closeCh
+
+	// Await synchronization
+	if dcCh != nil {
+		select {
+		case <-dcCh:
+		case <-time.After(time.Second):
+		}
+	}
+
+	delete(c.s.conns, c)
 }
 
 // PanicOnError panics if the connection has encountered an error.