diff --git a/internal/hub/hub.go b/internal/hub/hub.go
index 246b585..cc9f4df 100644
--- a/internal/hub/hub.go
+++ b/internal/hub/hub.go
@@ -53,18 +53,15 @@ func (h *Hub) Run() {
 		select {
 		case <-h.stop:
 			h.mu.Lock()
-			for conn, room := range h.connRoom {
-				conn.WriteMessage(websocket.CloseMessage,
-					websocket.FormatCloseMessage(websocket.CloseGoingAway, "server shutting down"))
-				conn.Close()
-				if clients, ok := h.rooms[room]; ok {
-					delete(clients, conn)
-					if len(clients) == 0 {
-						delete(h.rooms, room)
-					}
+			for _, clients := range h.rooms {
+				for conn := range clients {
+					conn.WriteMessage(websocket.CloseMessage,
+						websocket.FormatCloseMessage(websocket.CloseGoingAway, "server shutting down"))
+					conn.Close()
 				}
-				delete(h.connRoom, conn)
 			}
+			h.rooms = make(map[string]map[*websocket.Conn]bool)
+			h.connRoom = make(map[*websocket.Conn]string)
 			h.mu.Unlock()
 			metrics.ConnectedClients.Set(0)
 			h.logger.Info("Hub stopped, all clients disconnected")
diff --git a/internal/hub/hub_integration_test.go b/internal/hub/hub_integration_test.go
index b0bc8f0..077ef58 100644
--- a/internal/hub/hub_integration_test.go
+++ b/internal/hub/hub_integration_test.go
@@ -501,3 +501,72 @@ func TestIntegration_BroadcastToEmptyRoom(t *testing.T) {
 	}
 }
 
+func TestIntegration_GracefulShutdownMultiRoom(t *testing.T) {
+	logger := logging.NewLogger("debug", &bytes.Buffer{})
+	h := New(logger)
+	go h.Run()
+
+	s := httptest.NewServer(http.HandlerFunc(h.HandleWebSocket))
+	defer s.Close()
+
+	// Connect clients to different rooms
+	rooms := []string{"room-a", "room-b", "room-c"}
+	conns := make([]*websocket.Conn, 0, len(rooms))
+	for _, room := range rooms {
+		ws := dialWSWithRoom(t, s, room)
+		conns = append(conns, ws)
+	}
+
+	waitForClients(t, h, 3, time.Second)
+
+	// Verify all clients are connected to separate rooms
+	h.mu.RLock()
+	roomCount := len(h.rooms)
+	connCount := len(h.connRoom)
+	h.mu.RUnlock()
+	if roomCount != 3 {
+		t.Fatalf("expected 3 rooms, got %d", roomCount)
+	}
+	if connCount != 3 {
+		t.Fatalf("expected 3 connections, got %d", connCount)
+	}
+
+	// Shutdown the hub — all clients should receive close frame
+	h.Shutdown()
+
+	var wg sync.WaitGroup
+	for i, ws := range conns {
+		wg.Add(1)
+		go func(idx int, c *websocket.Conn) {
+			defer wg.Done()
+			c.SetReadDeadline(time.Now().Add(2 * time.Second))
+			_, _, err := c.ReadMessage()
+			if err == nil {
+				t.Errorf("client %d: expected error (close frame), got nil", idx)
+				return
+			}
+			closeErr, ok := err.(*websocket.CloseError)
+			if !ok {
+				t.Errorf("client %d: expected CloseError, got %T: %v", idx, err, err)
+				return
+			}
+			if closeErr.Code != websocket.CloseGoingAway {
+				t.Errorf("client %d: expected CloseGoingAway (%d), got %d",
+					idx, websocket.CloseGoingAway, closeErr.Code)
+			}
+		}(i, ws)
+	}
+	wg.Wait()
+
+	// Verify maps are cleared
+	h.mu.RLock()
+	roomsAfter := len(h.rooms)
+	connsAfter := len(h.connRoom)
+	h.mu.RUnlock()
+	if roomsAfter != 0 {
+		t.Errorf("expected 0 rooms after shutdown, got %d", roomsAfter)
+	}
+	if connsAfter != 0 {
+		t.Errorf("expected 0 connections after shutdown, got %d", connsAfter)
+	}
+}