diff --git fivestar.module fivestar.module
index 69a1cff..d7f00d5 100644
--- fivestar.module
+++ fivestar.module
@@ -973,8 +973,11 @@ function _fivestar_allow_vote($element) {
       'entity_type' => isset($element['#settings']['content_type']) ? $element['#settings']['content_type'] : NULL,
       'uid' => $user->uid,
     );
+    if( ! user_is_logged_in() ) {
+      $criteria['vote_source'] = ip_address();
+    }
 
-  $can_revote = !votingapi_select_votes($criteria);
+    $can_revote = !votingapi_select_votes($criteria);
   }
   if (!$can_revote) {
     return FALSE;