diff --git a/modules/search/search.admin.inc b/modules/search/search.admin.inc
index a609485..6397887 100644
--- a/modules/search/search.admin.inc
+++ b/modules/search/search.admin.inc
@@ -132,7 +132,7 @@ function search_admin_settings($form) {
   foreach (variable_get('search_active_modules', array('node', 'user')) as $module) {
     $added_form = module_invoke($module, 'search_admin');
     if (is_array($added_form)) {
-      $form = array_merge($form, $added_form);
+      $form = array_merge_recursive($form, $added_form);
     }
   }