diff --git a/lib/redmine_xapian.rb b/lib/redmine_xapian.rb
index bcb93e9..a2664ef 100644
--- a/lib/redmine_xapian.rb
+++ b/lib/redmine_xapian.rb
@@ -20,6 +20,8 @@
 
 # Libraries
 require "#{File.dirname(__FILE__)}/redmine_xapian/search_data"
+require "#{File.dirname(__FILE__)}/redmine_xapian/xapian_search"
+require "#{File.dirname(__FILE__)}/redmine_xapian/container_type_helper"
 require "#{File.dirname(__FILE__)}/redmine_xapian/xapian_search_service"
 
 # Patches
diff --git a/lib/redmine_xapian/xapian_search_service.rb b/lib/redmine_xapian/xapian_search_service.rb
index 2e5e9eb..221a238 100644
--- a/lib/redmine_xapian/xapian_search_service.rb
+++ b/lib/redmine_xapian/xapian_search_service.rb
@@ -21,7 +21,7 @@
 module RedmineXapian
   # Xapian search service
   class XapianSearchService
-    extend XapianSearch
+    extend RedmineXapian::XapianSearch
 
     class << self
       def search(search_data)