diff --git a/src/slic3r/GUI/GUI_App.cpp b/src/slic3r/GUI/GUI_App.cpp
index e8b0687bb..7ea3b62d8 100644
--- a/src/slic3r/GUI/GUI_App.cpp
+++ b/src/slic3r/GUI/GUI_App.cpp
@@ -4597,7 +4597,7 @@ void GUI_App::start_sync_user_preset(bool with_progress_dlg)
             });
         };
         cancelFn = [this, dlg]() {
-            return dlg->WasCanceled();
+            return m_is_closing || dlg->WasCanceled();
         };
         finishFn = [this, userid = m_agent->get_user_id(), dlg](bool ok) {
             CallAfter([=]{
@@ -4689,8 +4689,12 @@ void GUI_App::stop_sync_user_preset()
         return;
 
     enable_sync = false;
-    if (m_sync_update_thread.joinable())
-        m_sync_update_thread.detach();
+    if (m_sync_update_thread.joinable()) {
+        if (m_is_closing)
+            m_sync_update_thread.join();
+        else
+            m_sync_update_thread.detach();
+    }
 }
 
 void GUI_App::start_http_server()