diff --git a/lib/annotate.rb b/lib/annotate.rb
index eab454b40..4abe74088 100644
--- a/lib/annotate.rb
+++ b/lib/annotate.rb
@@ -54,7 +54,7 @@ def self.set_defaults(options = {})
     return if @has_set_defaults
     @has_set_defaults = true
 
-    options = HashWithIndifferentAccess.new(options)
+    options = ActiveSupport::HashWithIndifferentAccess.new(options)
 
     all_options.flatten.each do |key|
       if options.key?(key)