diff --git a/includes/og.field.inc b/includes/og.field.inc
index ebe93ff..1493bb6 100644
--- a/includes/og.field.inc
+++ b/includes/og.field.inc
@@ -258,12 +258,13 @@ function og_property_info_alter($wrapper, $info) {
 function og_get_mocked_instance($instance, $field_mode) {
   $mocked_instance = $instance;
   $widget_type = $instance['settings']['behaviors']['og_widget'][$field_mode]['widget_type'];
+  $widget_settings = isset($instance['settings']['behaviors']['og_widget'][$field_mode]['widget_settings']) ? $instance['settings']['behaviors']['og_widget'][$field_mode]['widget_settings'] : array();
   $mocked_instance['widget']['type'] = $widget_type;
 
   // Set the widget's module.
   $widget_info = field_info_widget_types($widget_type);
   $mocked_instance['widget']['module'] = $widget_info['module'];
-  $mocked_instance['widget']['settings'] = drupal_array_merge_deep($mocked_instance['widget']['settings'], $widget_info['settings']);
+  $mocked_instance['widget']['settings'] = drupal_array_merge_deep($widget_settings + $mocked_instance['widget']['settings'], $widget_info['settings']);
 
   // See OgSelectionHandler::buildEntityFieldQuery().
   $mocked_instance['field_mode'] = $field_mode;
diff --git a/plugins/entityreference/behavior/OgWidgetHandler.class.php b/plugins/entityreference/behavior/OgWidgetHandler.class.php
index 51f137f..b290dfa 100644
--- a/plugins/entityreference/behavior/OgWidgetHandler.class.php
+++ b/plugins/entityreference/behavior/OgWidgetHandler.class.php
@@ -19,9 +19,11 @@ class OgWidgetHandler extends EntityReference_BehaviorHandler_Abstract {
     $settings += array(
       'default' => array(
         'widget_type' => 'options_select',
+        'widget_settings' => array(),
       ),
       'admin' => array(
         'widget_type' => 'entityreference_autocomplete',
+        'widget_settings' => array(),
       ),
     );
 
@@ -39,8 +41,10 @@ class OgWidgetHandler extends EntityReference_BehaviorHandler_Abstract {
     module_load_include('inc', 'field_ui', 'field_ui.admin');
     $widget_types = field_ui_widget_type_options('entityreference');
     unset($widget_types['og_complex']);
+    $field_info_widget_types = field_info_widget_types();
 
     foreach ($field_types as $field_type => $value) {
+      $settings_id = 'og-' . $field_type . '-settings';
       $form[$field_type]['widget_type'] = array(
         '#type' => 'select',
         '#title' => $value['title'],
@@ -48,7 +52,36 @@ class OgWidgetHandler extends EntityReference_BehaviorHandler_Abstract {
         '#options' => $widget_types,
         '#default_value' => $settings[$field_type]['widget_type'],
         '#description' => $value['description'],
+        '#ajax' => array(
+          'callback' => 'og_' . $field_type . '_settings_form_ajax',
+          'wrapper' => $settings_id,
+          'method' => 'replace',
+          'event' => 'change',
+        ),
       );
+      $form[$field_type]['widget_settings'] = array(
+        '#type' => 'fieldset',
+        '#title' => t('@title Settings', array('@title' => $value['title'])),
+        '#tree' => TRUE,
+        '#attributes' => array(
+          'id' => $settings_id,
+        ),
+      );
+      if ($settings[$field_type]['widget_type'] && !empty($field_info_widget_types[$settings[$field_type]['widget_type']])) {
+        $widget_type = $field_info_widget_types[$settings[$field_type]['widget_type']];
+        $current_settings = isset($settings[$field_type]['widget_settings']) ?  $settings[$field_type]['widget_settings'] : array();
+        $fake_instance = array(
+          'widget' => array(
+            'type' => $settings[$field_type]['widget_type'],
+            'module' => $widget_type['module'],
+            'settings' => $current_settings,
+          ) + $instance['widget'],
+        ) + $instance;
+        $additions = module_invoke($widget_type['module'], 'field_widget_settings_form', $field, $fake_instance);
+        if ($additions) {
+          $form[$field_type]['widget_settings'] += $additions;
+        }
+      }
     }
 
     // Field access settings.