diff --git a/demos/gtk-demo/tree_store.c b/demos/gtk-demo/tree_store.c
index a7c22f2..0eea0c6 100644
--- a/demos/gtk-demo/tree_store.c
+++ b/demos/gtk-demo/tree_store.c
@@ -49,14 +49,14 @@ struct _TreeItem
 enum
 {
   COLUMN_0,
-  COLUMN_1,
   NUM_COLUMNS
 };
 
 /* tree data */
+static TreeItem D[] = {{ "I", NULL }, { "J", NULL }, { "K", NULL }, { NULL }};
 static TreeItem C[] = {{ "H", NULL }, { NULL }};
-static TreeItem A[] = {{ "C", C }, { "D", NULL }, { NULL }};
 static TreeItem B[] = {{ "E", NULL }, { "F", NULL }, { "G", NULL }, { NULL }};
+static TreeItem A[] = {{ "C", C }, { "D", D }, { NULL }};
 static TreeItem R[] = {{ "A", A }, { "B", B }, { NULL }};
 
 
@@ -69,8 +69,7 @@ create_model (void)
 
   /* create tree store */
   model = gtk_tree_store_new (NUM_COLUMNS,
-                              G_TYPE_STRING,
-                              G_TYPE_BOOLEAN);
+                              G_TYPE_STRING);
 
   /* add data to the tree store */
   while (item_0->label)
@@ -80,7 +79,6 @@ create_model (void)
       gtk_tree_store_append (model, &iter, NULL);
       gtk_tree_store_set (model, &iter,
                           COLUMN_0, item_0->label,
-                          COLUMN_1, item_1->label,
                           -1);
 
       /* add children */
@@ -91,7 +89,6 @@ create_model (void)
           gtk_tree_store_append (model, &child_iter, &iter);
           gtk_tree_store_set (model, &child_iter,
                               COLUMN_0, item_1->label,
-                              COLUMN_1, item_1->label,
                               -1);
 
           item_1++;