diff --git a/internal/loadbalance/slow_start.go b/internal/loadbalance/slow_start.go
index a8c8d8b..2a063d8 100644
--- a/internal/loadbalance/slow_start.go
+++ b/internal/loadbalance/slow_start.go
@@ -105,7 +105,7 @@ func (m *SlowStartManager) Start() {
 
 // Stop 停止后台更新。
 func (m *SlowStartManager) Stop() {
-	if !m.running.Load() {
+	if !m.running.Swap(false) {
 		return
 	}
 	close(m.stopCh)