Issue with nested resource

I'm trying to use nested resources to generate links to the responses
that exist in this category.

Instead of:
http://localhost:3000/categories/4/responses/4/edit
It generates this:
http://localhost:3000/categories/4%2F5/responses/4/edit

See that extra URL Encoded slash 5 (%2F5=/5)? Why is that showing up?

Here's my code:
<ul id="ul_questions">
  <% unless @category.responses.empty? %>
       <% @category.responses.each do |response| %>
      <li><%= link_to response.name,
edit_category_response_path([@category,response]) %></li>
    <% end %>
  <% end %>
</ul>

Okay. I got it. Apparently one shouldn't pass the parameters as an
array like in form_for:

edit_category_response_path(@category,response)