diff --git a/demos/gtk-demo/changedisplay.c b/demos/gtk-demo/changedisplay.c
index db89e1de3e..17d8448178 100644
--- a/demos/gtk-demo/changedisplay.c
+++ b/demos/gtk-demo/changedisplay.c
@@ -585,7 +585,7 @@ destroy_info (ChangeDisplayInfo *info)
 }
 
 static void
-destroy_cb (GtkObject          *object,
+destroy_cb (GObject            *object,
 	    ChangeDisplayInfo **info)
 {
   destroy_info (*info);
diff --git a/demos/gtk-demo/images.c b/demos/gtk-demo/images.c
index eb3f1d9484..e58d9c5d48 100644
--- a/demos/gtk-demo/images.c
+++ b/demos/gtk-demo/images.c
@@ -261,7 +261,7 @@ start_progressive_loading (GtkWidget *image)
 }
 
 static void
-cleanup_callback (GtkObject *object,
+cleanup_callback (GObject   *object,
 		  gpointer   data)
 {
   if (load_timeout)
diff --git a/demos/gtk-demo/pixbufs.c b/demos/gtk-demo/pixbufs.c
index 0095790e45..4cc7190497 100644
--- a/demos/gtk-demo/pixbufs.c
+++ b/demos/gtk-demo/pixbufs.c
@@ -186,7 +186,7 @@ timeout (gpointer data)
 static guint timeout_id;
 
 static void
-cleanup_callback (GtkObject *object,
+cleanup_callback (GObject   *object,
                   gpointer   data)
 {
   g_source_remove (timeout_id);
diff --git a/demos/pixbuf-demo.c b/demos/pixbuf-demo.c
index 3c3b261ba5..4448072eb3 100644
--- a/demos/pixbuf-demo.c
+++ b/demos/pixbuf-demo.c
@@ -173,7 +173,7 @@ static guint timeout_id;
 
 /* Destroy handler for the window */
 static void
-destroy_cb (GtkObject *object, gpointer data)
+destroy_cb (GObject *object, gpointer data)
 {
 	g_source_remove (timeout_id);
 	timeout_id = 0;