diff --git a/actionpack/lib/action_controller/routing/generation/polymorphic_routes.rb b/actionpack/lib/action_controller/routing/generation/polymorphic_routes.rb
index ee441602747db..2adf3575a7191 100644
--- a/actionpack/lib/action_controller/routing/generation/polymorphic_routes.rb
+++ b/actionpack/lib/action_controller/routing/generation/polymorphic_routes.rb
@@ -50,6 +50,7 @@ module PolymorphicRoutes
     #   polymorphic_url([blog, post]) # => "http://example.com/blogs/1/posts/1"
     #   polymorphic_url([:admin, blog, post]) # => "http://example.com/admin/blogs/1/posts/1"
     #   polymorphic_url([user, :blog, post]) # => "http://example.com/users/1/blog/posts/1"
+    #   polymorphic_url(Comment) # => "http://example.com/comments"
     #
     # ==== Options
     #
@@ -70,6 +71,9 @@ module PolymorphicRoutes
     #   record = Comment.new
     #   polymorphic_url(record)  # same as comments_url()
     #
+    #   # the class of a record will also map to the collection
+    #   polymorphic_url(Comment) # same as comments_url()
+    #
     def polymorphic_url(record_or_hash_or_array, options = {})
       if record_or_hash_or_array.kind_of?(Array)
         record_or_hash_or_array = record_or_hash_or_array.compact
@@ -93,6 +97,9 @@ def polymorphic_url(record_or_hash_or_array, options = {})
             (record.respond_to?(:destroyed?) && record.destroyed?)
         args.pop
         :plural
+      elsif record.is_a?(Class)
+        args.pop
+        :plural
       else
         :singular
       end
diff --git a/actionpack/test/activerecord/polymorphic_routes_test.rb b/actionpack/test/activerecord/polymorphic_routes_test.rb
index f001b0dab8bc8..37f1f6dff8798 100644
--- a/actionpack/test/activerecord/polymorphic_routes_test.rb
+++ b/actionpack/test/activerecord/polymorphic_routes_test.rb
@@ -45,6 +45,12 @@ def test_with_record
       assert_equal "http://example.com/projects/#{@project.id}", polymorphic_url(@project)
     end
   end
+  
+  def test_with_class
+    with_test_routes do
+      assert_equal "http://example.com/projects", polymorphic_url(@project.class)
+    end
+  end
 
   def test_with_new_record
     with_test_routes do 
@@ -144,6 +150,19 @@ def test_with_nested_destroyed
     end
   end
   
+  def test_with_nested_class
+    with_test_routes do
+      @project.save
+      assert_equal "http://example.com/projects/#{@project.id}/tasks", polymorphic_url([@project, @task.class])
+    end
+  end
+  
+  def test_class_with_array_and_namespace
+    with_admin_test_routes do 
+      assert_equal "http://example.com/admin/projects", polymorphic_url([:admin, @project.class])
+    end
+  end
+  
   def test_new_with_array_and_namespace
     with_admin_test_routes do 
       assert_equal "http://example.com/admin/projects/new", polymorphic_url([:admin, @project], :action => 'new')
@@ -267,6 +286,12 @@ def test_with_irregular_plural_record
     end
   end
   
+  def test_with_irregular_plural_class
+    with_test_routes do 
+      assert_equal "http://example.com/taxes", polymorphic_url(@tax.class)
+    end
+  end
+  
   def test_with_irregular_plural_new_record
     with_test_routes do 
       assert_equal "http://example.com/taxes", polymorphic_url(@tax)
@@ -320,6 +345,12 @@ def test_new_with_irregular_plural_array_and_namespace
     end
   end
   
+  def test_class_with_irregular_plural_array_and_namespace
+    with_admin_test_routes do 
+      assert_equal "http://example.com/admin/taxes", polymorphic_url([:admin, @tax.class])
+    end
+  end
+  
   def test_unsaved_with_irregular_plural_array_and_namespace
     with_admin_test_routes do 
       assert_equal "http://example.com/admin/taxes", polymorphic_url([:admin, @tax])