diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index c49ac70562..dcf98b729b 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -44,7 +44,8 @@ module ActionDispatch
             controller = "#{params[:controller].camelize}Controller"
             ActiveSupport::Inflector.constantize(controller)
           end
-        rescue NameError
+        rescue NameError => e
+          raise unless e.message.include?(controller)
           nil
         end