1 files changed, 6 insertions, 5 deletions
diff --git a/activesupport/lib/active_support/json.rb b/activesupport/lib/active_support/json.rb
index b2ebe9adc8..5072992cdf 100644
--- a/activesupport/lib/active_support/json.rb
+++ b/activesupport/lib/active_support/json.rb
@@ -28,13 +28,14 @@ module ActiveSupport
       }
 
       def self.escape(string)
-        json = '"' + string.gsub(escape_regex) { |s| ESCAPED_CHARS[s] }
-        json.force_encoding('ascii-8bit') if respond_to?(:force_encoding)
-        json.gsub(/([\xC0-\xDF][\x80-\xBF]|
+        string = string.dup.force_encoding(::Encoding::BINARY) if string.respond_to?(:force_encoding)
+        json = string.gsub(escape_regex) { |s| ESCAPED_CHARS[s] }.
+          gsub(/([\xC0-\xDF][\x80-\xBF]|
                  [\xE0-\xEF][\x80-\xBF]{2}|
                  [\xF0-\xF7][\x80-\xBF]{3})+/nx) { |s|
-          s.unpack("U*").pack("n*").unpack("H*")[0].gsub(/.{4}/, '\\\\u\&')
-        } + '"'
+            s.unpack("U*").pack("n*").unpack("H*")[0].gsub(/.{4}/, '\\\\u\&')
+          }
+        %("#{json}")
       end
     end