diff --git a/src/core/window-private.h b/src/core/window-private.h
index 0d5d68c6f..c0cf4f1b1 100644
--- a/src/core/window-private.h
+++ b/src/core/window-private.h
@@ -204,7 +204,6 @@ struct _MetaWindow
   char *gtk_menubar_object_path;
 
   Window xtransient_for;
-  Window xgroup_leader;
   MetaWindow *transient_for;
 
   /* Initial workspace property */
diff --git a/src/x11/group.c b/src/x11/group.c
index f08c75577..56e601bc0 100644
--- a/src/x11/group.c
+++ b/src/x11/group.c
@@ -36,6 +36,7 @@
 #include "x11/group-props.h"
 #include "x11/meta-x11-display-private.h"
 #include "x11/window-x11.h"
+#include "x11/window-x11-private.h"
 
 static MetaGroup*
 meta_group_new (MetaX11Display *x11_display,
@@ -141,16 +142,15 @@ meta_window_get_group (MetaWindow *window)
 }
 
 void
-meta_window_compute_group (MetaWindow* window)
+meta_window_compute_group (MetaWindow *window)
 {
-  MetaGroup *group;
+  MetaGroup *group = NULL;
   MetaWindow *ancestor;
   MetaX11Display *x11_display = window->display->x11_display;
+  Window win_leader = meta_window_x11_get_xgroup_leader (window);
 
   /* use window->xwindow if no window->xgroup_leader */
 
-  group = NULL;
-
   /* Determine the ancestor of the window; its group setting will override the
    * normal grouping rules; see bug 328211.
    */
@@ -160,9 +160,9 @@ meta_window_compute_group (MetaWindow* window)
     {
       if (ancestor != window)
         group = ancestor->group;
-      else if (window->xgroup_leader != None)
+      else if (win_leader != None)
         group = g_hash_table_lookup (x11_display->groups_by_leader,
-                                     &window->xgroup_leader);
+                                     &win_leader);
       else
         {
           Window xwindow = meta_window_x11_get_xwindow (window);
@@ -178,12 +178,14 @@ meta_window_compute_group (MetaWindow* window)
     }
   else
     {
-      if (ancestor != window && ancestor->xgroup_leader != None)
+      Window ancestor_leader = meta_window_x11_get_xgroup_leader (ancestor);
+
+      if (ancestor != window && ancestor_leader != None)
         group = meta_group_new (x11_display,
-                                ancestor->xgroup_leader);
-      else if (window->xgroup_leader != None)
+                                ancestor_leader);
+      else if (win_leader != None)
         group = meta_group_new (x11_display,
-                                window->xgroup_leader);
+                                win_leader);
       else
         group = meta_group_new (x11_display,
                                 meta_window_x11_get_xwindow (window));
diff --git a/src/x11/window-props.c b/src/x11/window-props.c
index 059f75a11..9ea0b51bf 100644
--- a/src/x11/window-props.c
+++ b/src/x11/window-props.c
@@ -1617,12 +1617,12 @@ reload_wm_hints (MetaWindow    *window,
   Window old_group_leader;
   gboolean urgent;
 
-  old_group_leader = window->xgroup_leader;
+  old_group_leader = priv->xgroup_leader;
 
   /* Fill in defaults */
   window->input = TRUE;
   window->initially_iconic = FALSE;
-  window->xgroup_leader = None;
+  priv->xgroup_leader = None;
   priv->wm_hints_pixmap = None;
   priv->wm_hints_mask = None;
   urgent = FALSE;
@@ -1638,7 +1638,7 @@ reload_wm_hints (MetaWindow    *window,
         window->initially_iconic = (hints->initial_state == IconicState);
 
       if (hints->flags & WindowGroupHint)
-        window->xgroup_leader = hints->window_group;
+        priv->xgroup_leader = hints->window_group;
 
       if (hints->flags & IconPixmapHint)
         priv->wm_hints_pixmap = hints->icon_pixmap;
@@ -1651,15 +1651,15 @@ reload_wm_hints (MetaWindow    *window,
 
       meta_verbose ("Read WM_HINTS input: %d iconic: %d group leader: 0x%lx pixmap: 0x%lx mask: 0x%lx",
                     window->input, window->initially_iconic,
-                    window->xgroup_leader,
+                    priv->xgroup_leader,
                     priv->wm_hints_pixmap,
                     priv->wm_hints_mask);
     }
 
-  if (window->xgroup_leader != old_group_leader)
+  if (priv->xgroup_leader != old_group_leader)
     {
       meta_verbose ("Window %s changed its group leader to 0x%lx",
-                    window->desc, window->xgroup_leader);
+                    window->desc, priv->xgroup_leader);
 
       meta_window_group_leader_changed (window);
     }
diff --git a/src/x11/window-x11-private.h b/src/x11/window-x11-private.h
index fa685571c..b309586f2 100644
--- a/src/x11/window-x11-private.h
+++ b/src/x11/window-x11-private.h
@@ -79,6 +79,7 @@ struct _MetaWindowX11Private
 
   Window xwindow;
   Window xclient_leader;
+  Window xgroup_leader;
 
   /* Bypass compositor hints */
   MetaBypassCompositorHint bypass_compositor;
@@ -90,4 +91,6 @@ MetaWindowX11Private * meta_window_x11_get_private (MetaWindowX11 *window_x11);
 
 void meta_window_x11_initialize_state (MetaWindow *window);
 
+Window meta_window_x11_get_xgroup_leader (MetaWindow *window);
+
 G_END_DECLS
diff --git a/src/x11/window-x11.c b/src/x11/window-x11.c
index 11e1f336c..f028c2f5c 100644
--- a/src/x11/window-x11.c
+++ b/src/x11/window-x11.c
@@ -558,7 +558,7 @@ meta_window_x11_manage (MetaWindow *window)
 
   /* assign the window to its group, or create a new group if needed */
   window->group = NULL;
-  window->xgroup_leader = None;
+  priv->xgroup_leader = None;
   meta_window_compute_group (window);
 
   meta_window_load_initial_properties (window);
@@ -2002,6 +2002,10 @@ static gboolean
 meta_window_x11_set_transient_for (MetaWindow *window,
                                    MetaWindow *parent)
 {
+  MetaWindowX11 *window_x11 = META_WINDOW_X11 (window);
+  MetaWindowX11Private *priv =
+    meta_window_x11_get_instance_private (window_x11);
+
   meta_window_x11_recalc_window_type (window);
   if (!window->constructing)
     {
@@ -2027,8 +2031,8 @@ meta_window_x11_set_transient_for (MetaWindow *window,
    * in programs such as xmms-- see #328211.
    */
   if (window->xtransient_for != None &&
-      window->xgroup_leader != None &&
-      window->xtransient_for != window->xgroup_leader)
+      priv->xgroup_leader != None &&
+      window->xtransient_for != priv->xgroup_leader)
     meta_window_group_leader_changed (window);
 
   return TRUE;
@@ -4412,3 +4416,17 @@ meta_window_x11_get_xwindow (MetaWindow *window)
 
   return priv->xwindow;
 }
+
+Window
+meta_window_x11_get_xgroup_leader (MetaWindow *window)
+{
+  MetaWindowX11 *window_x11;
+  MetaWindowX11Private *priv;
+
+  g_return_val_if_fail (META_IS_WINDOW (window), None);
+
+  window_x11 = META_WINDOW_X11 (window);
+  priv = meta_window_x11_get_instance_private (window_x11);
+
+  return priv->xgroup_leader;
+}