1 files changed, 6 insertions, 1 deletions
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index 6e7e133cc5..219fa37fcb 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -337,7 +337,12 @@ module ActionDispatch
             # Yes plz - JP
             included do
               routes.install_helpers(self)
-              singleton_class.send(:define_method, :_routes) { @_routes || routes }
+              singleton_class.send(:define_method, :_routes) { routes }
+            end
+
+            def initialize(*)
+              @_routes = nil
+              super
             end
 
             define_method(:_routes) { @_routes || routes }