diff --git a/geocoder.widget.inc b/geocoder.widget.inc
index a6a8400..07cfe8d 100644
--- a/geocoder.widget.inc
+++ b/geocoder.widget.inc
@@ -142,6 +142,7 @@ function geocoder_field_widget_settings_form($this_field, $instance) {
       }
 
       if (isset($handler['settings_callback'])) {
+        require_once $handler['path'] . '/' . $handler['file'];
         $settings_callback = $handler['settings_callback'];
         $form['handler_settings'][$handler_id] = array_merge($form['handler_settings'][$handler_id], $settings_callback($default_values));
       }