diff --git a/activesupport/lib/active_support/multibyte/utils.rb b/activesupport/lib/active_support/multibyte/utils.rb
index 094e856ea92ad..834ee03133a9f 100644
--- a/activesupport/lib/active_support/multibyte/utils.rb
+++ b/activesupport/lib/active_support/multibyte/utils.rb
@@ -1,39 +1,53 @@
 module ActiveSupport #:nodoc:
- module Multibyte #:nodoc:
-   # Returns a regular expression that matches valid characters in the current encoding
-   def self.valid_character
-     case $KCODE
-     when 'UTF8'
-       VALID_CHARACTER['UTF-8']
-     when 'SJIS'
-       VALID_CHARACTER['Shift_JIS']
-     end
-   end
+  module Multibyte #:nodoc:
+    # Returns a regular expression that matches valid characters in the current encoding
+    def self.valid_character
+      case $KCODE
+      when 'UTF8'
+        VALID_CHARACTER['UTF-8']
+      when 'SJIS'
+        VALID_CHARACTER['Shift_JIS']
+      end
+    end
 
-   # Verifies the encoding of a string
-   def self.verify(string)
-     if expression = valid_character
-       for c in string.split(//)
-         return false unless valid_character.match(c)
-       end
-     end
-     true
-   end
+    if 'string'.respond_to?(:valid_encoding?)
+      # Verifies the encoding of a string
+      def self.verify(string)
+        string.valid_encoding?
+      end
+    else
+      def self.verify(string)
+        if expression = valid_character
+          for c in string.split(//)
+            return false unless expression.match(c)
+          end
+        end
+        true
+      end
+    end
 
-   # Verifies the encoding of the string and raises an exception when it's not valid
-   def self.verify!(string)
-     raise ActiveSupport::Multibyte::Handlers::EncodingError.new("Found characters with invalid encoding") unless verify(string)
-   end
+    # Verifies the encoding of the string and raises an exception when it's not valid
+    def self.verify!(string)
+      raise ActiveSupport::Multibyte::Handlers::EncodingError.new("Found characters with invalid encoding") unless verify(string)
+    end
 
-   # Removes all invalid characters from the string
-   def self.clean(string)
-     if expression = valid_character
-       stripped = []; for c in string.split(//)
-         stripped << c if valid_character.match(c)
-       end; stripped.join
-     else
-       string
-     end
-   end
- end
-end
\ No newline at end of file
+    if 'string'.respond_to?(:force_encoding)
+      # Removes all invalid characters from the string.
+      #
+      # Note: this method is a no-op in Ruby 1.9
+      def self.clean(string)
+        string
+      end
+    else
+      def self.clean(string)
+        if expression = valid_character
+          stripped = []; for c in string.split(//)
+            stripped << c if expression.match(c)
+          end; stripped.join
+        else
+          string
+        end
+      end
+    end
+  end
+end