1 files changed, 2 insertions, 15 deletions
diff --git a/activesupport/lib/active_support/core_ext/enumerable.rb b/activesupport/lib/active_support/core_ext/enumerable.rb
index 35a8e0538c..c448d0454d 100644
--- a/activesupport/lib/active_support/core_ext/enumerable.rb
+++ b/activesupport/lib/active_support/core_ext/enumerable.rb
@@ -15,23 +15,10 @@ module Enumerable
   #   "2006-02-24 -> Transcript, Transcript"
   #   "2006-02-23 -> Transcript"
   def group_by
-    groups = []
-
-    inject({}) do |grouped, element|
-      index = yield(element)
-
-      if group = grouped[index]
-        group << element
-      else
-        group = [element]
-        groups << [index, group]
-        grouped[index] = group
-      end
-
+    inject ActiveSupport::OrderedHash.new do |grouped, element|
+      (grouped[yield(element)] ||= []) << element
       grouped
     end
-
-    groups
   end if RUBY_VERSION < '1.9'
 
   # Calculates a sum from the elements. Examples: