diff --git a/src/rtsp_manager.cpp b/src/rtsp_manager.cpp
index 8232c64..a749f74 100644
--- a/src/rtsp_manager.cpp
+++ b/src/rtsp_manager.cpp
@@ -120,8 +120,8 @@ gboolean RTSPManager::unmount_camera_in_main(gpointer data)
         auto it = mounted_factories.find(cam->name);
         if (it != mounted_factories.end())
         {
-            if (it->second)
-                g_object_unref(it->second); // 直接释放 factory
+            if (it->second && G_IS_OBJECT(it->second))
+                g_object_unref(it->second); // 安全 unref
             mounted_factories.erase(it);
         }
         streaming_status[cam->name] = false;