diff --git a/gtk/a11y/gtknotebookpageaccessible.c b/gtk/a11y/gtknotebookpageaccessible.c
index f6e0015269..8346c0ee66 100644
--- a/gtk/a11y/gtknotebookpageaccessible.c
+++ b/gtk/a11y/gtknotebookpageaccessible.c
@@ -22,6 +22,12 @@
 #include "gtknotebookpageaccessible.h"
 
 
+struct _GtkNotebookPageAccessiblePrivate
+{
+  GtkAccessible *notebook;
+  GtkWidget *child;
+};
+
 static void atk_component_interface_init (AtkComponentIface *iface);
 
 G_DEFINE_TYPE_WITH_CODE (GtkNotebookPageAccessible, _gtk_notebook_page_accessible, ATK_TYPE_OBJECT,
@@ -62,14 +68,14 @@ get_label_from_notebook_page (GtkNotebookPageAccessible *page)
   GtkWidget *child;
   GtkNotebook *notebook;
 
-  notebook = GTK_NOTEBOOK (gtk_accessible_get_widget (page->notebook));
+  notebook = GTK_NOTEBOOK (gtk_accessible_get_widget (page->priv->notebook));
   if (!notebook)
     return NULL;
 
   if (!gtk_notebook_get_show_tabs (notebook))
     return NULL;
 
-  child = gtk_notebook_get_tab_label (notebook, page->child);
+  child = gtk_notebook_get_tab_label (notebook, page->priv->child);
 
   if (GTK_IS_LABEL (child))
     return child;
@@ -102,7 +108,7 @@ gtk_notebook_page_accessible_get_parent (AtkObject *accessible)
 
   page = GTK_NOTEBOOK_PAGE_ACCESSIBLE (accessible);
 
-  return ATK_OBJECT (page->notebook);
+  return ATK_OBJECT (page->priv->notebook);
 }
 
 static gint
@@ -122,10 +128,10 @@ gtk_notebook_page_accessible_ref_child (AtkObject *accessible,
     return NULL;
 
   page = GTK_NOTEBOOK_PAGE_ACCESSIBLE (accessible);
-  if (!page->child)
+  if (!page->priv->child)
     return NULL;
 
-  child_obj = gtk_widget_get_accessible (page->child);
+  child_obj = gtk_widget_get_accessible (page->priv->child);
   g_object_ref (child_obj);
 
   return child_obj;
@@ -180,11 +186,11 @@ gtk_notebook_page_accessible_get_index_in_parent (AtkObject *accessible)
   GtkNotebookPageAccessible *page;
 
   page = GTK_NOTEBOOK_PAGE_ACCESSIBLE (accessible);
-  if (!page->child)
+  if (!page->priv->child)
     return -1;
 
-  return gtk_notebook_page_num (GTK_NOTEBOOK (gtk_accessible_get_widget (page->notebook)),
-                                page->child);
+  return gtk_notebook_page_num (GTK_NOTEBOOK (gtk_accessible_get_widget (page->priv->notebook)),
+                                page->priv->child);
 }
 
 static void
@@ -198,11 +204,16 @@ _gtk_notebook_page_accessible_class_init (GtkNotebookPageAccessibleClass *klass)
   class->ref_child = gtk_notebook_page_accessible_ref_child;
   class->ref_state_set = gtk_notebook_page_accessible_ref_state_set;
   class->get_index_in_parent = gtk_notebook_page_accessible_get_index_in_parent;
+
+  g_type_class_add_private (klass, sizeof (GtkNotebookPageAccessiblePrivate));
 }
 
 static void
 _gtk_notebook_page_accessible_init (GtkNotebookPageAccessible *page)
 {
+  page->priv = G_TYPE_INSTANCE_GET_PRIVATE (page,
+                                            GTK_TYPE_NOTEBOOK_PAGE_ACCESSIBLE,
+                                            GtkNotebookPageAccessiblePrivate);
 }
 
 static void
@@ -229,8 +240,8 @@ _gtk_notebook_page_accessible_new (GtkNotebookAccessible *notebook,
   object = g_object_new (GTK_TYPE_NOTEBOOK_PAGE_ACCESSIBLE, NULL);
 
   page = GTK_NOTEBOOK_PAGE_ACCESSIBLE (object);
-  page->notebook = GTK_ACCESSIBLE (notebook);
-  page->child = child;
+  page->priv->notebook = GTK_ACCESSIBLE (notebook);
+  page->priv->child = child;
 
   atk_object = ATK_OBJECT (page);
   atk_object->role = ATK_ROLE_PAGE_TAB;
@@ -238,7 +249,7 @@ _gtk_notebook_page_accessible_new (GtkNotebookAccessible *notebook,
 
   atk_object_set_parent (gtk_widget_get_accessible (child), atk_object);
 
-  g_signal_connect (gtk_accessible_get_widget (page->notebook),
+  g_signal_connect (gtk_accessible_get_widget (page->priv->notebook),
                     "child-notify::tab-label",
                     G_CALLBACK (notify_tab_label), page);
 
@@ -251,15 +262,15 @@ _gtk_notebook_page_accessible_invalidate (GtkNotebookPageAccessible *page)
   AtkObject *obj = ATK_OBJECT (page);
   GtkWidget *notebook;
 
-  notebook = gtk_accessible_get_widget (page->notebook);
+  notebook = gtk_accessible_get_widget (page->priv->notebook);
   if (notebook)
     g_signal_handlers_disconnect_by_func (notebook, notify_tab_label, page);
 
   atk_object_notify_state_change (obj, ATK_STATE_DEFUNCT, TRUE);
   atk_object_set_parent (obj, NULL);
-  page->notebook = NULL;
-  atk_object_set_parent (gtk_widget_get_accessible (page->child), NULL);
-  page->child = NULL;
+  page->priv->notebook = NULL;
+  atk_object_set_parent (gtk_widget_get_accessible (page->priv->child), NULL);
+  page->priv->child = NULL;
 }
 
 static AtkObject*
diff --git a/gtk/a11y/gtknotebookpageaccessible.h b/gtk/a11y/gtknotebookpageaccessible.h
index 1ccc2b61f6..6bd454fb32 100644
--- a/gtk/a11y/gtknotebookpageaccessible.h
+++ b/gtk/a11y/gtknotebookpageaccessible.h
@@ -29,15 +29,15 @@ G_BEGIN_DECLS
 #define GTK_IS_NOTEBOOK_PAGE_ACCESSIBLE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GTK_TYPE_NOTEBOOK_PAGE_ACCESSIBLE))
 #define GTK_NOTEBOOK_PAGE_ACCESSIBLE_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GTK_TYPE_NOTEBOOK_PAGE_ACCESSIBLE, GtkNotebookPageAccessibleClass))
 
-typedef struct _GtkNotebookPageAccessible      GtkNotebookPageAccessible;
-typedef struct _GtkNotebookPageAccessibleClass GtkNotebookPageAccessibleClass;
+typedef struct _GtkNotebookPageAccessible        GtkNotebookPageAccessible;
+typedef struct _GtkNotebookPageAccessibleClass   GtkNotebookPageAccessibleClass;
+typedef struct _GtkNotebookPageAccessiblePrivate GtkNotebookPageAccessiblePrivate;
 
 struct _GtkNotebookPageAccessible
 {
   AtkObject parent;
 
-  GtkAccessible *notebook;
-  GtkWidget *child;
+  GtkNotebookPageAccessiblePrivate *priv;
 };
 
 struct _GtkNotebookPageAccessibleClass