diff -ruN libwnck-2.31.0/libwnck/window.c libwnck-2.31.0_patched/libwnck/window.c
--- libwnck-2.31.0/libwnck/window.c	2019-01-22 15:38:31.268583945 +0300
+++ libwnck-2.31.0_patched/libwnck/window.c	2019-01-22 15:41:58.361913354 +0300
@@ -2900,12 +2900,6 @@
       else if (atoms[i] == _wnck_atom_get ("_NET_WM_ACTION_BELOW"))
         window->priv->actions |= WNCK_WINDOW_ACTION_BELOW;
 
-      else
-        {
-          const char *name = _wnck_atom_name (atoms [i]);
-          g_warning ("Unhandled action type %s", name ? name: "(nil)");
-        }
-
       i++;
     }