diff --git a/actionpack/lib/action_controller/failsafe.rb b/actionpack/lib/action_controller/failsafe.rb
index 42ec57025841c..d452913efc3c6 100644
--- a/actionpack/lib/action_controller/failsafe.rb
+++ b/actionpack/lib/action_controller/failsafe.rb
@@ -62,11 +62,11 @@ def failsafe_response_body
       
       # The default 500.html uses the h() method.
       def h(text) # :nodoc:
-        ERB::Util.h(text)
+        SafeERB::Util.h(text)
       end
       
       def render_template(filename)
-        ERB.new(File.read(filename)).result(binding)
+        SafeERB.new(File.read(filename)).result(binding)
       end
 
       def log_failsafe_exception(exception)
diff --git a/actionpack/lib/action_view/base.rb b/actionpack/lib/action_view/base.rb
index f10a26629a928..9f229d6be6f57 100644
--- a/actionpack/lib/action_view/base.rb
+++ b/actionpack/lib/action_view/base.rb
@@ -160,7 +160,7 @@ def initialize(paths, path, template_format = nil)
   #
   # See the ActionView::Helpers::PrototypeHelper::GeneratorMethods documentation for more details.
   class Base
-    include Helpers, Partials, ::ERB::Util
+    include Helpers, Partials, ::SafeERB::Util
     extend ActiveSupport::Memoizable
 
     attr_accessor :base_path, :assigns, :template_extension
diff --git a/actionpack/lib/action_view/helpers/active_record_helper.rb b/actionpack/lib/action_view/helpers/active_record_helper.rb
index ed407c9df2c78..fac887ef252f0 100644
--- a/actionpack/lib/action_view/helpers/active_record_helper.rb
+++ b/actionpack/lib/action_view/helpers/active_record_helper.rb
@@ -121,7 +121,7 @@ def error_message_on(object, method, *args)
         if (obj = (object.respond_to?(:errors) ? object : instance_variable_get("@#{object}"))) &&
           (errors = obj.errors.on(method))
           content_tag("div",
-            "#{options[:prepend_text]}#{ERB::Util.html_escape(errors.is_a?(Array) ? errors.first : errors)}#{options[:append_text]}".html_safe,
+            "#{options[:prepend_text]}#{SafeERB::Util.html_escape(errors.is_a?(Array) ? errors.first : errors)}#{options[:append_text]}".html_safe,
             :class => options[:css_class]
           )
         else
@@ -198,7 +198,7 @@ def error_messages_for(*params)
               locale.t :header, :count => count, :model => object_name
             end
             message = options.include?(:message) ? options[:message] : locale.t(:body)
-            error_messages = objects.sum {|object| object.errors.full_messages.map {|msg| content_tag(:li, ERB::Util.html_escape(msg)) } }.join.html_safe
+            error_messages = objects.sum {|object| object.errors.full_messages.map {|msg| content_tag(:li, SafeERB::Util.html_escape(msg)) } }.join.html_safe
 
             contents = ''
             contents << content_tag(options[:header_tag] || :h2, header_message) unless header_message.blank?
diff --git a/actionpack/lib/action_view/helpers/form_options_helper.rb b/actionpack/lib/action_view/helpers/form_options_helper.rb
index 6d5acf1726fd7..a720459505129 100644
--- a/actionpack/lib/action_view/helpers/form_options_helper.rb
+++ b/actionpack/lib/action_view/helpers/form_options_helper.rb
@@ -97,7 +97,7 @@ module Helpers
     #   </select>
     #
     module FormOptionsHelper
-      include ERB::Util
+      include SafeERB::Util
 
       # Create a select tag and a series of contained option tags for the provided object and method.
       # The option currently held by the object will be selected, provided that the object is available.
diff --git a/actionpack/lib/action_view/helpers/tag_helper.rb b/actionpack/lib/action_view/helpers/tag_helper.rb
index cdd348aecc4ba..ad46d13abcecd 100644
--- a/actionpack/lib/action_view/helpers/tag_helper.rb
+++ b/actionpack/lib/action_view/helpers/tag_helper.rb
@@ -6,7 +6,7 @@ module Helpers #:nodoc:
     # Provides methods to generate HTML tags programmatically when you can't use
     # a Builder. By default, they output XHTML compliant tags.
     module TagHelper
-      include ERB::Util
+      include SafeERB::Util
 
       BOOLEAN_ATTRIBUTES = %w(disabled readonly multiple checked).to_set
       BOOLEAN_ATTRIBUTES.merge(BOOLEAN_ATTRIBUTES.map(&:to_sym))
@@ -103,7 +103,7 @@ def cdata_section(content)
       #   escape_once("&lt;&lt; Accept & Checkout")
       #   # => "&lt;&lt; Accept &amp; Checkout"
       def escape_once(html)
-        ActiveSupport::Multibyte.clean(html.to_s).gsub(/[\"><]|&(?!([a-zA-Z]+|(#\d+));)/) { |special| ERB::Util::HTML_ESCAPE[special] }
+        ActiveSupport::Multibyte.clean(html.to_s).gsub(/[\"><]|&(?!([a-zA-Z]+|(#\d+));)/) { |special| SafeERB::Util::HTML_ESCAPE[special] }
       end
 
       private
diff --git a/actionpack/lib/action_view/template_handlers/erb.rb b/actionpack/lib/action_view/template_handlers/erb.rb
index e3120ba267ad2..d34a336df410b 100644
--- a/actionpack/lib/action_view/template_handlers/erb.rb
+++ b/actionpack/lib/action_view/template_handlers/erb.rb
@@ -11,7 +11,7 @@ class ERB < TemplateHandler
       self.erb_trim_mode = '-'
 
       def compile(template)
-        src = ::ERB.new("<% __in_erb_template=true %>#{template.source}", nil, erb_trim_mode, '@output_buffer').src
+        src = ::SafeERB.new("<% __in_erb_template=true %>#{template.source}", nil, erb_trim_mode, '@output_buffer').src
 
         # Ruby 1.9 prepends an encoding to the source. However this is
         # useless because you can only set an encoding on the first line
diff --git a/actionpack/test/controller/output_escaping_test.rb b/actionpack/test/controller/output_escaping_test.rb
index 43a8c05cdaf84..a68d03a511e9f 100644
--- a/actionpack/test/controller/output_escaping_test.rb
+++ b/actionpack/test/controller/output_escaping_test.rb
@@ -3,17 +3,17 @@
 class OutputEscapingTest < ActiveSupport::TestCase
 
   test "escape_html shouldn't die when passed nil" do
-    assert ERB::Util.h(nil).blank?
+    assert SafeERB::Util.h(nil).blank?
   end
 
   test "escapeHTML should escape strings" do
-    assert_equal "&lt;&gt;&quot;", ERB::Util.h("<>\"")
+    assert_equal "&lt;&gt;&quot;", SafeERB::Util.h("<>\"")
   end
 
   test "escapeHTML shouldn't touch explicitly safe strings" do
     # TODO this seems easier to compose and reason about, but
     # this should be verified
-    assert_equal "<", ERB::Util.h("<".html_safe)
+    assert_equal "<", SafeERB::Util.h("<".html_safe)
   end
 
 end
diff --git a/actionpack/test/template/erb_util_test.rb b/actionpack/test/template/erb_util_test.rb
index 06f095470d0f1..c7b416ace4858 100644
--- a/actionpack/test/template/erb_util_test.rb
+++ b/actionpack/test/template/erb_util_test.rb
@@ -1,16 +1,16 @@
 require 'abstract_unit'
 
 class ErbUtilTest < Test::Unit::TestCase
-  include ERB::Util
+  include SafeERB::Util
 
-  ERB::Util::HTML_ESCAPE.each do |given, expected|
+  SafeERB::Util::HTML_ESCAPE.each do |given, expected|
     define_method "test_html_escape_#{expected.gsub /\W/, ''}" do
       assert_equal expected, html_escape(given)
     end
 
     unless given == '"'
       define_method "test_json_escape_#{expected.gsub /\W/, ''}" do
-        assert_equal ERB::Util::JSON_ESCAPE[given], json_escape(given)
+        assert_equal SafeERB::Util::JSON_ESCAPE[given], json_escape(given)
       end
     end
   end
diff --git a/activesupport/lib/active_support/core_ext/string/output_safety.rb b/activesupport/lib/active_support/core_ext/string/output_safety.rb
index c200c72240b74..9c0b89a4fc41f 100644
--- a/activesupport/lib/active_support/core_ext/string/output_safety.rb
+++ b/activesupport/lib/active_support/core_ext/string/output_safety.rb
@@ -1,7 +1,6 @@
 require 'erb'
 
-class ERB
-  undef :set_eoutvar
+class SafeERB < ERB
   def set_eoutvar(compiler, eoutvar = '_erbout')
     compiler.put_cmd = "#{eoutvar}.safe_concat"
     compiler.insert_cmd = "#{eoutvar}.safe_concat"
@@ -39,7 +38,6 @@ def html_escape(s)
       end
     end
 
-    undef :h
     alias h html_escape
 
     module_function :html_escape
@@ -84,7 +82,7 @@ def concat(value)
       if value.html_safe?
         super(value)
       else
-        super(ERB::Util.h(value))
+        super(SafeERB::Util.h(value))
       end
     end
     alias << concat
diff --git a/railties/guides/rails_guides/generator.rb b/railties/guides/rails_guides/generator.rb
index 6c0d9f3c3b132..e292bcadeaaea 100644
--- a/railties/guides/rails_guides/generator.rb
+++ b/railties/guides/rails_guides/generator.rb
@@ -122,7 +122,7 @@ def textile(body)
     def with_workaround_for_notextile(body)
       code_blocks = []
       body.gsub!(%r{<(yaml|shell|ruby|erb|html|sql|plain)>(.*?)</\1>}m) do |m|
-        es = ERB::Util.h($2)
+        es = SafeERB::Util.h($2)
         css_class = ['erb', 'shell'].include?($1) ? 'html' : $1
         code_blocks << %{<div class="code_container"><code class="#{css_class}">#{es}</code></div>}
         "\ndirty_workaround_for_notextile_#{code_blocks.size - 1}\n"
diff --git a/railties/guides/rails_guides/textile_extensions.rb b/railties/guides/rails_guides/textile_extensions.rb
index b22be5752def1..89c8ed2ddc9ae 100644
--- a/railties/guides/rails_guides/textile_extensions.rb
+++ b/railties/guides/rails_guides/textile_extensions.rb
@@ -32,7 +32,7 @@ def plusplus(body)
 
     def code(body)
       body.gsub!(%r{<(yaml|shell|ruby|erb|html|sql|plain)>(.*?)</\1>}m) do |m|
-        es = ERB::Util.h($2)
+        es = SafeERB::Util.h($2)
         css_class = ['erb', 'shell'].include?($1) ? 'html' : $1
         %{<notextile><div class="code_container"><code class="#{css_class}">#{es}</code></div></notextile>}
       end