diff --git a/modules/taxonomy/taxonomy.pages.inc b/modules/taxonomy/taxonomy.pages.inc
index 0cca252..5836eca 100644
--- a/modules/taxonomy/taxonomy.pages.inc
+++ b/modules/taxonomy/taxonomy.pages.inc
@@ -76,14 +76,14 @@ function taxonomy_term_feed($term) {
 /**
  * Helper function for autocompletion
  */
-function taxonomy_autocomplete($field_name, $tags_typed = '') {
+function taxonomy_autocomplete($field_name = '', $tags_typed = '') {
   $field = field_info_field($field_name);
 
   // The user enters a comma-separated list of tags. We only autocomplete the last tag.
   $tags_typed = drupal_explode_tags($tags_typed);
   $tag_last = drupal_strtolower(array_pop($tags_typed));
 
-  $matches = array();
+  $matches = $term_matches = array();
   if ($tag_last != '') {
 
     // Part of the criteria for the query come from the field's own settings.