diff --git a/tests/examples/ges-ui.c b/tests/examples/ges-ui.c
index 73419a3c55..a890c25c9e 100644
--- a/tests/examples/ges-ui.c
+++ b/tests/examples/ges-ui.c
@@ -61,6 +61,9 @@ void app_selection_changed_cb (GtkTreeSelection * selection, App * app);
 gboolean duration_scale_change_value_cb (GtkRange * range, GtkScrollType
     unused, gdouble value, App * app);
 
+void duration_cell_func (GtkTreeViewColumn * column, GtkCellRenderer * renderer,
+    GtkTreeModel * model, GtkTreeIter * iter, gpointer user);
+
 gboolean create_ui (App * app);
 
 void connect_to_filesource (GESTimelineObject * object, App * app);
@@ -124,6 +127,18 @@ duration_scale_change_value_cb (GtkRange * range, GtkScrollType unused,
   return TRUE;
 }
 
+void
+duration_cell_func (GtkTreeViewColumn * column, GtkCellRenderer * renderer,
+    GtkTreeModel * model, GtkTreeIter * iter, gpointer user)
+{
+  gchar buf[30];
+  guint64 duration;
+
+  gtk_tree_model_get (model, iter, 1, &duration, -1);
+  g_snprintf (buf, sizeof (buf), "%u:%02u:%02u.%09u", GST_TIME_ARGS (duration));
+  g_object_set (renderer, "text", &buf, NULL);
+}
+
 /* application methods ******************************************************/
 
 static void selection_foreach (GtkTreeModel * model, GtkTreePath * path,
@@ -388,6 +403,8 @@ create_ui (App * app)
 {
   GtkBuilder *builder;
   GtkTreeView *timeline;
+  GtkTreeViewColumn *duration_col;
+  GtkCellRenderer *duration_renderer;
 
   /* construct widget tree */
 
@@ -401,6 +418,8 @@ create_ui (App * app)
   GET_WIDGET (app->properties, "properties", GTK_WIDGET);
   GET_WIDGET (app->main_window, "window", GTK_WIDGET);
   GET_WIDGET (app->duration, "duration_scale", GTK_HSCALE);
+  GET_WIDGET (duration_col, "duration_column", GTK_TREE_VIEW_COLUMN);
+  GET_WIDGET (duration_renderer, "duration_renderer", GTK_CELL_RENDERER);
 
   /* we care when the tree selection changes */
 
@@ -417,6 +436,11 @@ create_ui (App * app)
     goto fail;
   gtk_tree_view_set_model (timeline, GTK_TREE_MODEL (app->model));
 
+  /* register custom cell data function */
+
+  gtk_tree_view_column_set_cell_data_func (duration_col, duration_renderer,
+      duration_cell_func, NULL, NULL);
+
   /* register callbacks on GES objects */
 
   g_signal_connect (app->layer, "object-added",
diff --git a/tests/examples/ges-ui.glade b/tests/examples/ges-ui.glade
index 454db25234..31e73c97bc 100644
--- a/tests/examples/ges-ui.glade
+++ b/tests/examples/ges-ui.glade
@@ -200,7 +200,7 @@
                         <property name="sizing">autosize</property>
                         <property name="title">Duration</property>
                         <child>
-                          <object class="GtkCellRendererText" id="cellrenderertext1"/>
+                          <object class="GtkCellRendererText" id="duration_renderer"/>
                           <attributes>
                             <attribute name="text">1</attribute>
                           </attributes>