diff --git a/guides/source/upgrading_ruby_on_rails.md b/guides/source/upgrading_ruby_on_rails.md
index 950290d106..eff00f7276 100644
--- a/guides/source/upgrading_ruby_on_rails.md
+++ b/guides/source/upgrading_ruby_on_rails.md
@@ -131,6 +131,10 @@ The order in which helpers from more than one directory are loaded has changed i
 
 Active Record Observer and Action Controller Sweeper have been extracted to the `rails-observers` gem. You will need to add the `rails-observers` gem if you require these features.
 
+### sass-rails
+
+* `asset_url` with two arguments is deprecated. For example: `asset-url("rails.png", image)` becomes `asset-url("rails.png")`
+
 Upgrading from Rails 3.1 to Rails 3.2
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