diff --git a/demos/gtk-demo/tree_store.c b/demos/gtk-demo/tree_store.c
index 4b6e257..67d81bf 100644
--- a/demos/gtk-demo/tree_store.c
+++ b/demos/gtk-demo/tree_store.c
@@ -70,9 +70,11 @@ static TreeItem R[] = {{ "A", A }, { "B", B }, { NULL }};
 static TreeItem O[] = {{ "R", R }, { NULL }}; //  Artefact added for symetry
 
 static GtkTreeModel *
-iterate_node(GtkTreeStore *model, TreeItem *parent, TreeItem *children)
+iterate_node(GtkTreeStore *model,
+             TreeItem    *item_parent,  TreeItem    *item_children,
+             GtkTreeIter *iter_parent,  GtkTreeIter *iter_children)
 {
-  printf("parent, children : %s, %s\n", parent->label, children->label);
+  printf("parent, children : %s -> %s\n", item_parent->label, item_children->label);
   /* gtk_tree_store_append (model, &child_child_iter, &child_iter); */
   /* gtk_tree_store_set (model, &child_child_iter, COLUMN_0, item_2->label, -1); */
   return GTK_TREE_MODEL (model);
@@ -85,22 +87,22 @@ create_model (void)
 
   TreeItem *item_0 = O->children;
   while (item_0->label) {
-      iterate_node(model, O, item_0);
       GtkTreeIter iter;
+      iterate_node(model, O, item_0, model, &iter);
       gtk_tree_store_append (model, &iter, NULL);
       gtk_tree_store_set (model, &iter, COLUMN_0, item_0->label, -1);
 
       TreeItem *item_1 = item_0->children;
       while (item_1->label) {
-          iterate_node(model, item_0, item_1);
           GtkTreeIter child_iter;
+          iterate_node(model, item_0, item_1, &iter, &child_iter);
           gtk_tree_store_append (model, &child_iter, &iter);
           gtk_tree_store_set (model, &child_iter, COLUMN_0, item_1->label, -1);
 
           TreeItem *item_2 = item_1->children;
           while (item_2->label) {
-              iterate_node(model, item_1, item_2);
               GtkTreeIter child_child_iter;
+              iterate_node(model, item_1, item_2, &child_iter, &child_child_iter);
               gtk_tree_store_append (model, &child_child_iter, &child_iter);
               gtk_tree_store_set (model, &child_child_iter, COLUMN_0, item_2->label, -1);