diff --git a/Gtk4_Reset/src/core/MyStack.cpp b/Gtk4_Reset/src/core/MyStack.cpp
index a569d76..6320df9 100644
--- a/Gtk4_Reset/src/core/MyStack.cpp
+++ b/Gtk4_Reset/src/core/MyStack.cpp
@@ -17,6 +17,8 @@ static void back_activated(GSimpleAction *actions,
 {
     // Show preferences window
     MyPrefs *prefs = main_win_get_prefs(MAIN_WIN(win));
+    my_prefs_first_load(prefs);
+    my_prefs_start_scan(prefs);
     gtk_window_present(GTK_WINDOW(prefs));
 }
 
diff --git a/Gtk4_Reset/src/ui/MyDock.cpp b/Gtk4_Reset/src/ui/MyDock.cpp
index e97da6e..02ea8a3 100644
--- a/Gtk4_Reset/src/ui/MyDock.cpp
+++ b/Gtk4_Reset/src/ui/MyDock.cpp
@@ -146,6 +146,7 @@ static gboolean prefs_win_closed(GtkWidget *window, MyDock *dock)
 {
     // For the preferences window, hide it
     gtk_widget_set_visible(window, FALSE);
+    my_prefs_stop_scan(dock->prefs_win);
     gtk_image_set_from_icon_name(GTK_IMAGE(dock->image_set), "my_prefs");
     return TRUE;
 }
diff --git a/Gtk4_Reset/src/ui/MyPrefs.cpp b/Gtk4_Reset/src/ui/MyPrefs.cpp
index f738ba4..2594a34 100644
--- a/Gtk4_Reset/src/ui/MyPrefs.cpp
+++ b/Gtk4_Reset/src/ui/MyPrefs.cpp
@@ -62,6 +62,7 @@ struct _MyPrefs
     gboolean panel_mode;                           // Whether panel mode is activated
     DockPos dock_pos;                              // Dock Position
     str_vec back_vec;                              // Vector of backgrounds
+    gboolean scan_ctrl;                            // Control the scan func
 };
 
 G_DEFINE_TYPE(MyPrefs, my_prefs, GTK_TYPE_WINDOW)
@@ -609,7 +610,7 @@ static gboolean scan_func(gpointer data)
     {
         load_image(file_name, image_item_index, is_internal, prefs);
     }
-    return TRUE;
+    return prefs->scan_ctrl;
 }
 
 void my_prefs_first_load(MyPrefs *self)
@@ -875,9 +876,16 @@ static void my_prefs_class_init(MyPrefsClass *klass)
 void my_prefs_start_scan(MyPrefs *self)
 {
     // Add timer to scan the list
+    self->scan_ctrl = TRUE;
     g_timeout_add(1, scan_func, self);
 }
 
+void my_prefs_stop_scan(MyPrefs *self)
+{
+    // Stop scan for background update
+    self->scan_ctrl = FALSE;
+}
+
 // Get Dock position
 DockPos my_prefs_get_dock_pos(MyPrefs *self)
 {
diff --git a/Gtk4_Reset/src/ui/MyPrefs.h b/Gtk4_Reset/src/ui/MyPrefs.h
index e169780..e90d011 100644
--- a/Gtk4_Reset/src/ui/MyPrefs.h
+++ b/Gtk4_Reset/src/ui/MyPrefs.h
@@ -13,6 +13,8 @@ G_DECLARE_FINAL_TYPE(MyPrefs, my_prefs, MY, PREFS, GtkWindow)
 
 void my_prefs_start_scan(MyPrefs *self);
 
+void my_prefs_stop_scan(MyPrefs *self);
+
 void my_prefs_first_load(MyPrefs *self);
 
 DockPos my_prefs_get_dock_pos(MyPrefs *self);