diff --git a/actionpack/CHANGELOG.md b/actionpack/CHANGELOG.md
index 0545d36a0a..ebb8277220 100644
--- a/actionpack/CHANGELOG.md
+++ b/actionpack/CHANGELOG.md
@@ -1,5 +1,17 @@
 ## Rails 3.2.0 (unreleased) ##
 
+*   form_for with +:as+ option uses "#{action}_#{as}" as css class and id:
+
+    Before:
+
+        form_for(@user, :as => 'client') # => "<form class="client_new">..."
+
+    Now:
+
+        form_for(@user, :as => 'client') # => "<form class="new_client">..."
+
+    *Vasiliy Ermolovich*
+
 *   Allow rescue responses to be configured through a railtie as in `config.action_dispatch.rescue_responses`. Please look at ActiveRecord::Railtie for an example *José Valim*
 
 *   Allow fresh_when/stale? to take a record instead of an options hash *DHH*
diff --git a/actionpack/lib/action_view/helpers/form_helper.rb b/actionpack/lib/action_view/helpers/form_helper.rb
index e674e12509..1a64b12aa6 100644
--- a/actionpack/lib/action_view/helpers/form_helper.rb
+++ b/actionpack/lib/action_view/helpers/form_helper.rb
@@ -387,8 +387,8 @@ module ActionView
         as = options[:as]
         action, method = object.respond_to?(:persisted?) && object.persisted? ? [:edit, :put] : [:new, :post]
         options[:html].reverse_merge!(
-          :class  => as ? "#{as}_#{action}" : dom_class(object, action),
-          :id     => as ? "#{as}_#{action}" : [options[:namespace], dom_id(object, action)].compact.join("_").presence,
+          :class  => as ? "#{action}_#{as}" : dom_class(object, action),
+          :id     => as ? "#{action}_#{as}" : [options[:namespace], dom_id(object, action)].compact.join("_").presence,
           :method => method
         )
 
diff --git a/actionpack/test/template/form_helper_test.rb b/actionpack/test/template/form_helper_test.rb
index 3fee366804..41e925b000 100644
--- a/actionpack/test/template/form_helper_test.rb
+++ b/actionpack/test/template/form_helper_test.rb
@@ -769,7 +769,7 @@ class FormHelperTest < ActionView::TestCase
       concat f.submit('Create post')
     end
 
-    expected =  whole_form("/posts/123", "create-post", "other_name_edit", :method => "put") do
+    expected =  whole_form("/posts/123", "create-post", "edit_other_name", :method => "put") do
       "<label for='other_name_title' class='post_title'>Title</label>" +
       "<input name='other_name[title]' size='30' id='other_name_title' value='Hello World' type='text' />" +
       "<textarea name='other_name[body]' id='other_name_body' rows='20' cols='40'>Back to the hill and over it again!</textarea>" +
@@ -906,7 +906,7 @@ class FormHelperTest < ActionView::TestCase
       concat f.check_box(:secret)
     end
 
-    expected = whole_form('/posts/123', 'post[]_edit', 'post[]_edit', 'put') do
+    expected = whole_form('/posts/123', 'edit_post[]', 'edit_post[]', 'put') do
       "<label for='post_123_title'>Title</label>" +
       "<input name='post[123][title]' size='30' type='text' id='post_123_title' value='Hello World' />" +
       "<textarea name='post[123][body]' id='post_123_body' rows='20' cols='40'>Back to the hill and over it again!</textarea>" +
@@ -924,7 +924,7 @@ class FormHelperTest < ActionView::TestCase
       concat f.check_box(:secret)
     end
 
-    expected = whole_form('/posts/123', 'post[]_edit', 'post[]_edit', 'put') do
+    expected = whole_form('/posts/123', 'edit_post[]', 'edit_post[]', 'put') do
       "<input name='post[][title]' size='30' type='text' id='post__title' value='Hello World' />" +
       "<textarea name='post[][body]' id='post__body' rows='20' cols='40'>Back to the hill and over it again!</textarea>" +
       "<input name='post[][secret]' type='hidden' value='0' />" +
@@ -1066,7 +1066,7 @@ class FormHelperTest < ActionView::TestCase
       concat f.submit
     end
 
-    expected = whole_form('/posts/123', 'another_post_edit', 'another_post_edit', :method => 'put') do
+    expected = whole_form('/posts/123', 'edit_another_post', 'edit_another_post', :method => 'put') do
       "<input name='commit' type='submit' value='Update your Post' />"
     end
 
@@ -1098,7 +1098,7 @@ class FormHelperTest < ActionView::TestCase
       }
     end
 
-    expected = whole_form('/posts/123', 'post[]_edit', 'post[]_edit', 'put') do
+    expected = whole_form('/posts/123', 'edit_post[]', 'edit_post[]', 'put') do
       "<input name='post[123][title]' size='30' type='text' id='post_123_title' value='Hello World' />" +
       "<input name='post[123][comment][][name]' size='30' type='text' id='post_123_comment__name' value='new comment' />"
     end
@@ -1157,7 +1157,7 @@ class FormHelperTest < ActionView::TestCase
       }
     end
 
-    expected = whole_form('/posts/123', 'post[]_edit', 'post[]_edit', 'put') do
+    expected = whole_form('/posts/123', 'edit_post[]', 'edit_post[]', 'put') do
       "<input name='post[123][comment][title]' size='30' type='text' id='post_123_comment_title' value='Hello World' />"
     end
 
@@ -1185,7 +1185,7 @@ class FormHelperTest < ActionView::TestCase
       }
     end
 
-    expected = whole_form('/posts/123', 'post[]_edit', 'post[]_edit', 'put') do
+    expected = whole_form('/posts/123', 'edit_post[]', 'edit_post[]', 'put') do
       "<input name='post[123][comment][123][title]' size='30' type='text' id='post_123_comment_123_title' value='Hello World' />"
     end
 
@@ -1205,9 +1205,9 @@ class FormHelperTest < ActionView::TestCase
       }
     end
 
-    expected = whole_form('/posts/123', 'post[]_edit', 'post[]_edit', 'put') do
+    expected = whole_form('/posts/123', 'edit_post[]', 'edit_post[]', 'put') do
       "<input name='post[123][comment][5][title]' size='30' type='text' id='post_123_comment_5_title' value='Hello World' />"
-    end + whole_form('/posts/123', 'post_edit', 'post_edit', 'put') do
+    end + whole_form('/posts/123', 'edit_post', 'edit_post', 'put') do
       "<input name='post[1][comment][123][title]' size='30' type='text' id='post_1_comment_123_title' value='Hello World' />"
     end
 
@@ -1860,7 +1860,7 @@ class FormHelperTest < ActionView::TestCase
       }
     end
 
-    expected = whole_form('/posts/123', 'create-post', 'post_edit', :method => 'put') do
+    expected = whole_form('/posts/123', 'create-post', 'edit_post', :method => 'put') do
       "<input name='post[title]' size='30' type='text' id='post_title' value='Hello World' />" +
       "<textarea name='post[body]' id='post_body' rows='20' cols='40'>Back to the hill and over it again!</textarea>" +
       "<input name='parent_post[secret]' type='hidden' value='0' />" +
@@ -1880,7 +1880,7 @@ class FormHelperTest < ActionView::TestCase
       }
     end
 
-    expected = whole_form('/posts/123', 'create-post', 'post_edit', :method => 'put') do
+    expected = whole_form('/posts/123', 'create-post', 'edit_post', :method => 'put') do
       "<input name='post[title]' size='30' type='text' id='post_title' value='Hello World' />" +
       "<textarea name='post[body]' id='post_body' rows='20' cols='40'>Back to the hill and over it again!</textarea>" +
       "<input name='post[comment][name]' type='text' id='post_comment_name' value='new comment' size='30' />"