diff --git a/gds-render-gui.c b/gds-render-gui.c
index a251487..55a0a32 100644
--- a/gds-render-gui.c
+++ b/gds-render-gui.c
@@ -41,6 +41,10 @@
 #include "tree-renderer/lib-cell-renderer.h"
 #include "gds-parser/gds-tree-checker.h"
 
+enum gds_render_gui_signal_sig_ids {SIGNAL_WINDOW_CLOSED = 0, SIGNAL_COUNT};
+
+static guint gds_render_gui_signals[SIGNAL_COUNT];
+
 struct _GdsRenderGui {
 	/* Parent GObject */
 	GObject parent;
@@ -78,6 +82,11 @@ static gboolean on_window_close(gpointer window, GdkEvent *event, gpointer user)
 	g_clear_object(&self->main_window);
 	gtk_widget_destroy(GTK_WIDGET(window));
 
+	/* Delete loaded library data */
+	clear_lib_list(&self->gds_libraries);
+
+	g_signal_emit(self, gds_render_gui_signals[SIGNAL_WINDOW_CLOSED], 0);
+
 	return TRUE;
 }
 
@@ -424,13 +433,14 @@ static void gds_render_gui_dispose(GObject *gobject)
 
 	self = RENDERER_GUI(gobject);
 
+	clear_lib_list(&self->gds_libraries);
+
 	g_clear_object(&self->cell_tree_view);
 	g_clear_object(&self->convert_button);
 	g_clear_object(&self->layer_selector);
 	g_clear_object(&self->cell_tree_store);
 	g_clear_object(&self->cell_search_entry);
 
-
 	if (self->main_window) {
 		g_signal_handlers_destroy(self->main_window);
 		gtk_widget_destroy(GTK_WIDGET(self->main_window));
@@ -445,6 +455,17 @@ static void gds_render_gui_class_init(GdsRenderGuiClass *klass)
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
 
+	gds_render_gui_signals[SIGNAL_WINDOW_CLOSED] =
+			g_signal_newv("window-closed", RENDERER_TYPE_GUI,
+				      G_SIGNAL_RUN_LAST | G_SIGNAL_NO_RECURSE,
+				      NULL,
+				      NULL,
+				      NULL,
+				      NULL,
+				      G_TYPE_NONE,
+				      0,
+				      NULL);
+
 	gobject_class->dispose = gds_render_gui_dispose;
 }
 
diff --git a/main.c b/main.c
index 990bf52..6d2effc 100644
--- a/main.c
+++ b/main.c
@@ -71,6 +71,15 @@ const static GActionEntry app_actions[] = {
 	{"about", app_about, NULL, NULL, NULL, {0}}
 };
 
+static void gui_window_closed_callback(GdsRenderGui *gui, gpointer user_data)
+{
+	GList **gui_list = (GList **)user_data;
+
+	/* Dispose of Gui element */
+	*gui_list = g_list_remove(*gui_list, gui);
+	g_object_unref(gui);
+}
+
 static void gapp_activate(GApplication *app, gpointer user_data)
 {
 	GtkWindow *main_window;
@@ -81,6 +90,8 @@ static void gapp_activate(GApplication *app, gpointer user_data)
 	gui = gds_render_gui_new();
 	appdata->gui_list = g_list_append(appdata->gui_list, gui);
 
+	g_signal_connect(gui, "window-closed", G_CALLBACK(gui_window_closed_callback), &appdata->gui_list);
+
 	main_window = gds_render_gui_get_main_window(gui);
 
 	gtk_application_add_window(GTK_APPLICATION(app), main_window);
@@ -127,12 +138,6 @@ static int start_gui(int argc, char **argv)
 	app_status = g_application_run(G_APPLICATION(gapp), argc, argv);
 	g_object_unref(gapp);
 
-	/* Destroy gui_list */
-	for (list_iter = appdata.gui_list; list_iter != NULL; list_iter = g_list_next(list_iter)) {
-		gui = RENDERER_GUI(list_iter->data);
-		g_object_unref(gui);
-	}
-
 	g_list_free(appdata.gui_list);
 
 	return app_status;