diff --git a/activesupport/lib/active_support.rb b/activesupport/lib/active_support.rb
index d049740002..e4fa3b40e5 100644
--- a/activesupport/lib/active_support.rb
+++ b/activesupport/lib/active_support.rb
@@ -33,7 +33,6 @@ module ActiveSupport
   autoload :Cache, 'active_support/cache'
   autoload :Callbacks, 'active_support/callbacks'
   autoload :Deprecation, 'active_support/deprecation'
-  autoload :Duration, 'active_support/duration'
   autoload :Gzip, 'active_support/gzip'
   autoload :Inflector, 'active_support/inflector'
   autoload :Memoizable, 'active_support/memoizable'
diff --git a/activesupport/lib/active_support/core/time/autoload.rb b/activesupport/lib/active_support/core/time/autoload.rb
index 6970c398c3..c9a7731b39 100644
--- a/activesupport/lib/active_support/core/time/autoload.rb
+++ b/activesupport/lib/active_support/core/time/autoload.rb
@@ -1,4 +1,5 @@
 module ActiveSupport
+  autoload :Duration, 'active_support/duration'
   autoload :TimeWithZone, 'active_support/time_with_zone'
   autoload :TimeZone, 'active_support/values/time_zone'
 end