diff --git a/gtk/gtktexttag.h b/gtk/gtktexttag.h
index 454cd93861..a314ab766a 100644
--- a/gtk/gtktexttag.h
+++ b/gtk/gtktexttag.h
@@ -86,11 +86,9 @@ struct _GtkTextTagClass
 {
   GObjectClass parent_class;
 
-  /* Padding for future expansion */
-  void (*_gtk_reserved1) (void);
-  void (*_gtk_reserved2) (void);
-  void (*_gtk_reserved3) (void);
-  void (*_gtk_reserved4) (void);
+  /*< private >*/
+
+  gpointer padding[8];
 };
 
 GDK_AVAILABLE_IN_ALL