diff --git a/gtk/gtkscale.c b/gtk/gtkscale.c
index c57549486e..70369410bf 100644
--- a/gtk/gtkscale.c
+++ b/gtk/gtkscale.c
@@ -137,6 +137,7 @@
 
 typedef struct _GtkScaleMark GtkScaleMark;
 
+typedef struct _GtkScalePrivate       GtkScalePrivate;
 struct _GtkScalePrivate
 {
   GSList       *marks;
diff --git a/gtk/gtkscale.h b/gtk/gtkscale.h
index 31151cb850..a76cd81f53 100644
--- a/gtk/gtkscale.h
+++ b/gtk/gtkscale.h
@@ -44,7 +44,6 @@ G_BEGIN_DECLS
 
 
 typedef struct _GtkScale              GtkScale;
-typedef struct _GtkScalePrivate       GtkScalePrivate;
 typedef struct _GtkScaleClass         GtkScaleClass;
 
 struct _GtkScale
@@ -63,11 +62,9 @@ struct _GtkScaleClass
                                gint     *x,
                                gint     *y);
 
-  /* 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