diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index b757df6f22a0a36ffa4b8db14619df5ed1b4c595..d55064bf6df391d11adb4e94059db5ed8ff340b9 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -48,6 +48,8 @@
 
 *Rails 3.1.1 (unreleased)*
 
+* Set relative url root in assets when controller isn't available for Sprockets (eg. Sass files using asset_path). Fixes #2435 [Guillermo Iguaran]
+
 * Fixed the behavior of asset pipeline when config.assets.digest and config.assets.compile are false and requested asset isn't precompiled.
   Before the requested asset were compiled anyway ignoring that the config.assets.compile flag is false. [Guillermo Iguaran]
 
diff --git a/actionpack/lib/sprockets/helpers/rails_helper.rb b/actionpack/lib/sprockets/helpers/rails_helper.rb
index 3987e6e17fa4d82246ca5e74fa771ffcf46cdb70..7d9296fa90cac093b420526a57921b04d316cb37 100644
--- a/actionpack/lib/sprockets/helpers/rails_helper.rb
+++ b/actionpack/lib/sprockets/helpers/rails_helper.rb
@@ -17,6 +17,7 @@ def asset_paths
           paths.asset_digests     = asset_digests
           paths.compile_assets    = compile_assets?
           paths.digest_assets     = digest_assets?
+          paths.relative_url_root = config.action_controller.relative_url_root
           paths
         end
       end
@@ -96,12 +97,17 @@ def asset_environment
       end
 
       class AssetPaths < ::ActionView::AssetPaths #:nodoc:
-        attr_accessor :asset_environment, :asset_prefix, :asset_digests, :compile_assets, :digest_assets
+        attr_accessor :asset_environment, :asset_prefix, :asset_digests, :compile_assets,
+                      :digest_assets, :relative_url_root
 
         class AssetNotPrecompiledError < StandardError; end
 
-        def compute_public_path(source, dir, ext=nil, include_host=true, protocol=nil)
-          super(source, asset_prefix, ext, include_host, protocol)
+        def compute_public_path(source, dir, ext = nil, include_host = true, protocol = nil)
+          public_path = super(source, asset_prefix, ext, include_host, protocol)
+          if !is_uri?(public_path) && relative_url_root
+            public_path = rewrite_relative_url_root(public_path, relative_url_root)
+          end
+          public_path
         end
 
         # Return the filesystem path for the source
@@ -149,6 +155,10 @@ def rewrite_extension(source, dir, ext)
             source
           end
         end
+
+        def relative_url_root
+          has_request? ? super : @relative_url_root
+        end
       end
     end
   end
diff --git a/actionpack/test/template/sprockets_helper_test.rb b/actionpack/test/template/sprockets_helper_test.rb
index ae4cb1f0aaa9d0eff1ba11c3e949b0080f3cc710..105c6417124959c96e050ea0f7672df53787d422 100644
--- a/actionpack/test/template/sprockets_helper_test.rb
+++ b/actionpack/test/template/sprockets_helper_test.rb
@@ -124,6 +124,13 @@ def url_for(*args)
      asset_path("/images/logo.gif")
   end
 
+  test "asset path with relative url root when controller isn't present but relative_url_root is" do
+    @controller = nil
+    @config.action_controller.relative_url_root = "/collaboration/hieraki"
+    assert_equal "/collaboration/hieraki/images/logo.gif",
+     asset_path("/images/logo.gif")
+  end
+
   test "javascript path" do
     assert_match %r{/assets/application-[0-9a-f]+.js},
       asset_path(:application, "js")