diff -up ./plugins/thunar-wallpaper/twp-provider.c.orig ./plugins/thunar-wallpaper/twp-provider.c
--- ./plugins/thunar-wallpaper/twp-provider.c.orig	2015-02-15 21:54:11.672972742 +0200
+++ ./plugins/thunar-wallpaper/twp-provider.c	2015-02-15 21:54:25.470434346 +0200
@@ -171,7 +171,7 @@ twp_provider_get_file_actions (ThunarxMe
             {
               action = g_object_new (GTK_TYPE_ACTION,
                                      "name", "Twp::setwallpaper",
-                                     "icon-name", "background",
+                                     "icon-name", "preferences-desktop-wallpaper",
                                      "label", _("Set as wallpaper"),
                                      NULL);
               g_signal_connect (action, "activate", G_CALLBACK (twp_action_set_wallpaper), files->data);