diff --git a/demos/gtk-demo/list_store.c b/demos/gtk-demo/list_store.c
index 156ddf6cd4..94335afdf8 100644
--- a/demos/gtk-demo/list_store.c
+++ b/demos/gtk-demo/list_store.c
@@ -276,7 +276,7 @@ do_list_store (GtkWidget *do_widget)
     {
       gtk_widget_show_all (window);
       if (timeout == 0) {
-        //FIXME this should use the animation-duration instead
+        /* FIXME this should use the animation-duration instead */
         timeout = g_timeout_add (80, spinner_timeout, NULL);
       }
     }