diff --git a/app_win_2_back.cpp b/app_win_2_back.cpp
index 0c44c12..7addbd1 100644
--- a/app_win_2_back.cpp
+++ b/app_win_2_back.cpp
@@ -107,7 +107,7 @@ namespace gui_to_app {
         }
     }
 
-    void AppWin2Back::on_quit() {
+    void AppWin2Back::on_quit() noexcept {
         auto windows = get_windows();
         for (auto *window: windows) {
             window->set_visible(false);
diff --git a/app_win_2_back.hpp b/app_win_2_back.hpp
index 4f2d1e2..f7693c6 100644
--- a/app_win_2_back.hpp
+++ b/app_win_2_back.hpp
@@ -28,7 +28,7 @@ namespace gui_to_app {
         void on_activate() final;
 
     private:
-        void on_quit();
+        void on_quit() noexcept;
 
         learn_gtkmm4::HelloWorld *main_window{ nullptr };
         Gtk::Switch *sword_switch{ nullptr };