diff --git a/filecache.inc b/filecache.inc
index 9e46a60..4cd7f6c 100644
--- a/filecache.inc
+++ b/filecache.inc
@@ -204,9 +204,10 @@ class DrupalFileCache implements DrupalCacheInterface {
       $cache = $this->get($cid);
       if ($cache !== FALSE) {
         $results[$cid] = $cache;
-        unset($cids[$cid]);
       }
     }
+    $cids = array_diff($cids, array_keys($results));
+
     return $results;
   }