diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index c118c72440199..93ed6a8737989 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -511,7 +511,7 @@ def member_name
 
           # Checks for uncountable plurals, and appends "_index" if they're.
           def collection_name
-            singular == plural ? "#{plural}_index" : plural
+            singular == plural ? "#{name}_index" : name
           end
 
           def resource_scope
diff --git a/actionpack/test/dispatch/routing_test.rb b/actionpack/test/dispatch/routing_test.rb
index 3f090b72540ba..55235b6e9e2f5 100644
--- a/actionpack/test/dispatch/routing_test.rb
+++ b/actionpack/test/dispatch/routing_test.rb
@@ -188,6 +188,7 @@ def self.matches?(request)
       end
 
       resources :sheep
+      resources :taxis
 
       resources :clients do
         namespace :google do
@@ -965,6 +966,14 @@ def test_resources_for_uncountable_names
       assert_equal '/sheep/1/edit', edit_sheep_path(1)
     end
   end
+  
+  def test_named_paths_for_resources_with_irregular_plural_of_the_plural
+    with_test_routes do
+      assert_equal '/taxis/1', taxi_path(1)
+      assert_equal '/taxis', taxis_path
+      assert_raise(NameError) { taxes_path }
+    end
+  end
 
   def test_path_names
     with_test_routes do