1 files changed, 1 insertions, 2 deletions
diff --git a/actionpack/lib/action_controller/routing/builder.rb b/actionpack/lib/action_controller/routing/builder.rb
index 4740113ed0..b8323847fd 100644
--- a/actionpack/lib/action_controller/routing/builder.rb
+++ b/actionpack/lib/action_controller/routing/builder.rb
@@ -67,10 +67,9 @@ module ActionController
         options = options.dup
 
         if options[:namespace]
-          options[:controller] = "#{options[:path_prefix]}/#{options[:controller]}"
+          options[:controller] = "#{options.delete(:namespace).sub(/\/$/, '')}/#{options[:controller]}"
           options.delete(:path_prefix)
           options.delete(:name_prefix)
-          options.delete(:namespace)
         end
 
         requirements = (options.delete(:requirements) || {}).dup