diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 617a9029b..200bc1c2c 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -1270,8 +1270,21 @@ module ApplicationHelper
   end
 
   def favicon
-    fav_path = (current_theme && current_theme.favicon?) ? current_theme.favicon_path : '/favicon.ico'
-    "<link rel='shortcut icon' href='#{image_path(fav_path)}' />".html_safe
+    "<link rel='shortcut icon' href='#{favicon_path}' />".html_safe
+  end
+
+  # Returns the path to the favicon
+  def favicon_path
+    icon = (current_theme && current_theme.favicon?) ? current_theme.favicon_path : '/favicon.ico'
+    image_path(icon)
+  end
+
+  # Returns the full URL to the favicon
+  def favicon_url
+    # TODO: use #image_url introduced in Rails4
+    path = favicon_path
+    base = url_for(:controller => 'welcome', :action => 'index', :only_path => false)
+    base.sub(%r{/+$},'') + '/' + path.sub(%r{^/+},'')
   end
 
   def robot_exclusion_tag
diff --git a/test/unit/helpers/application_helper_test.rb b/test/unit/helpers/application_helper_test.rb
index 82d55702a..00a157757 100644
--- a/test/unit/helpers/application_helper_test.rb
+++ b/test/unit/helpers/application_helper_test.rb
@@ -1264,4 +1264,26 @@ RAW
     assert_equal '<h2>Foo &#187; Bar</h2>', title('Foo', 'Bar')
     assert_equal 'Bar - Foo - Redmine', html_title
   end
+
+  def test_favicon_path
+    assert_match %r{^/favicon\.ico}, favicon_path
+  end
+
+  def test_favicon_path_with_suburi
+    Redmine::Utils.relative_url_root = '/foo'
+    assert_match %r{^/foo/favicon\.ico}, favicon_path
+  ensure
+    Redmine::Utils.relative_url_root = ''
+  end
+
+  def test_favicon_url
+    assert_match %r{^http://test\.host/favicon\.ico}, favicon_url
+  end
+
+  def test_favicon_url_with_suburi
+    Redmine::Utils.relative_url_root = '/foo'
+    assert_match %r{^http://test\.host/foo/favicon\.ico}, favicon_url
+  ensure
+    Redmine::Utils.relative_url_root = ''
+  end
 end