3 files changed, 31 insertions, 2 deletions
diff --git a/ext/json/lib/json/add/ostruct.rb b/ext/json/lib/json/add/ostruct.rb
index e064c85ff4..686cf0025d 100644
--- a/ext/json/lib/json/add/ostruct.rb
+++ b/ext/json/lib/json/add/ostruct.rb
@@ -23,7 +23,7 @@ class OpenStruct
     }
   end
 
-  # Stores class name (OpenStruct) with this struct's values <tt>v</tt> as a
+  # Stores class name (OpenStruct) with this struct's values <tt>t</tt> as a
   # JSON string.
   def to_json(*args)
     as_json.to_json(*args)
diff --git a/ext/json/lib/json/add/set.rb b/ext/json/lib/json/add/set.rb
new file mode 100644
index 0000000000..71e2a0ac8b
--- /dev/null
+++ b/ext/json/lib/json/add/set.rb
@@ -0,0 +1,29 @@
+unless defined?(::JSON::JSON_LOADED) and ::JSON::JSON_LOADED
+  require 'json'
+end
+defined?(::Set) or require 'set'
+
+class Set
+  # Import a JSON Marshalled object.
+  #
+  # method used for JSON marshalling support.
+  def self.json_create(object)
+    new object['a']
+  end
+
+  # Marshal the object to JSON.
+  #
+  # method used for JSON marshalling support.
+  def as_json(*)
+    {
+      JSON.create_id => self.class.name,
+      'a'            => to_a,
+    }
+  end
+
+  # return the JSON value
+  def to_json(*args)
+    as_json.to_json(*args)
+  end
+end
+
diff --git a/ext/json/lib/json/version.rb b/ext/json/lib/json/version.rb
index b65ed87f98..115eb5bb9a 100644
--- a/ext/json/lib/json/version.rb
+++ b/ext/json/lib/json/version.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: false
 module JSON
   # JSON version
-  VERSION         = '2.1.0'
+  VERSION         = '2.2.0'
   VERSION_ARRAY   = VERSION.split(/\./).map { |x| x.to_i } # :nodoc:
   VERSION_MAJOR   = VERSION_ARRAY[0] # :nodoc:
   VERSION_MINOR   = VERSION_ARRAY[1] # :nodoc: