diff --git a/lib/searchkick/reindex.rb b/lib/searchkick/reindex.rb
index b0130c6..9b5e49e 100644
--- a/lib/searchkick/reindex.rb
+++ b/lib/searchkick/reindex.rb
@@ -115,9 +115,9 @@ module Searchkick
         # choosing a place for the synonym filter when stemming is not easy
         # https://groups.google.com/forum/#!topic/elasticsearch/p7qcQlgHdB8
         # TODO use a snowball stemmer on synonyms when creating the token filter
-        settings[:analysis][:analyzer][:default_index][:filter].insert(-4, "searchkick_synonym")
+        settings[:analysis][:analyzer][:default_index][:filter].insert(4, "searchkick_synonym")
         settings[:analysis][:analyzer][:default_index][:filter] << "searchkick_synonym"
-        settings[:analysis][:analyzer][:searchkick_search][:filter].insert(-4, "searchkick_synonym")
+        settings[:analysis][:analyzer][:searchkick_search][:filter].insert(4, "searchkick_synonym")
         settings[:analysis][:analyzer][:searchkick_search][:filter] << "searchkick_synonym"
         settings[:analysis][:analyzer][:searchkick_search2][:filter] << "searchkick_synonym"
       end
--
libgit2 0.21.0