diff --git a/lib/json_builder/extensions.rb b/lib/json_builder/extensions.rb
index c6d3ebc..1e94a20 100644
--- a/lib/json_builder/extensions.rb
+++ b/lib/json_builder/extensions.rb
@@ -13,6 +13,16 @@ def to_builder
 end
 
 class String
+  JS_ESCAPE_MAP = {
+    '\\'    => '\\\\',
+    '</'    => '<\/',
+    "\r\n"  => '\n',
+    "\n"    => '\n',
+    "\r"    => '\n',
+    '"'     => '\\"',
+    "'"     => "\\'"
+  }
+
   def to_builder
     %("#{json_escape}")
   end
@@ -20,10 +30,9 @@ def to_builder
   private
 
   def json_escape
-    self.gsub(/\n/, '\\n').
-         gsub(/\r/, '\\r').
-         gsub(/\t/, '\\t').
-         gsub(/\f/, '\\f')
+    gsub(/(\\|<\/|\r\n|\342\200\250|\342\200\251|[\n\r"'])/u) { |match|
+      JS_ESCAPE_MAP[match]
+    }
   end
 end
 
diff --git a/test/member_test.rb b/test/member_test.rb
index b774912..2c2b0f6 100644
--- a/test/member_test.rb
+++ b/test/member_test.rb
@@ -39,6 +39,10 @@ def test_custom_class
     assert_equal '"hello": "olleh"', member('hello', Dozer.new('hello')).to_s
   end
 
+  def test_double_quoted_value
+    assert_equal '"hello": "\"Hello\" he said"', member('hello', '"Hello" he said').to_s
+  end
+
   def test_without_key
     assert_raises(JSONBuilder::MissingKeyError) { member(nil, true).to_s }
   end
diff --git a/test/value_test.rb b/test/value_test.rb
index 1374d3b..ee3429a 100644
--- a/test/value_test.rb
+++ b/test/value_test.rb
@@ -64,4 +64,8 @@ def test_hash_value
   def test_custom_class
     assert_equal '"olleh"', value(Dozer.new('hello'))
   end
+
+  def test_double_quoted_value
+    assert_equal '"\"hello\""', value('"hello"')
+  end
 end