diff --git a/Lib/Search/BookSearch.php b/Lib/Search/BookSearch.php
index 3eed0bf..0ab5a5d 100644
--- a/Lib/Search/BookSearch.php
+++ b/Lib/Search/BookSearch.php
@@ -98,7 +98,7 @@ class BookSearch
 
     public function addRange($field, $min = '*', $max = '*')
     {
-        $this->queryParts[] = sprintf('%s:[%s TO %s]', $field, $min, $max);
+        $this->filterQueryParts[] = sprintf('%s:[%s TO %s]', $field, $min, $max);
     }
 
     public function addSortField($field, $order = \SolrQuery::ORDER_DESC)