diff --git a/.travis.yml b/.travis.yml
index ef3807c..c1be87b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,10 +1,10 @@
 language: ruby
 
 rvm:
-  - 1.9.3
-  - 2.0
   - 2.1
   - 2.2.2
+  - 2.3.4
+  - 2.4.1
 
 gemfile:
  - Gemfile
diff --git a/fluent-plugin-gcloud-pubsub.gemspec b/fluent-plugin-gcloud-pubsub.gemspec
index d97910a..ea9a173 100644
--- a/fluent-plugin-gcloud-pubsub.gemspec
+++ b/fluent-plugin-gcloud-pubsub.gemspec
@@ -16,7 +16,7 @@ Gem::Specification.new do |gem|
   gem.executables = `git ls-files -- bin/*`.split("\n").map{ |f| File.basename(f) }
   gem.require_paths = ['lib']
 
-  gem.add_runtime_dependency "fluentd", "~> 0.12.0"
+  gem.add_runtime_dependency "fluentd", [">= 0.14.15", "< 2"]
   gem.add_runtime_dependency "gcloud", "= 0.6.3"
   gem.add_runtime_dependency "fluent-plugin-buffer-lightening", ">= 0.0.2"
 
diff --git a/lib/fluent/plugin/in_gcloud_pubsub.rb b/lib/fluent/plugin/in_gcloud_pubsub.rb
index 80a4d8c..cc92f48 100644
--- a/lib/fluent/plugin/in_gcloud_pubsub.rb
+++ b/lib/fluent/plugin/in_gcloud_pubsub.rb
@@ -1,40 +1,34 @@
 require 'gcloud'
-require 'fluent/input'
-require 'fluent/parser'
+require 'fluent/plugin/input'
+require 'fluent/plugin/parser'
 
-module Fluent
+module Fluent::Plugin
   class GcloudPubSubInput < Input
     Fluent::Plugin.register_input('gcloud_pubsub', self)
 
+    helpers :parser, :thread
+
     config_param :tag,                :string
     config_param :project,            :string,  :default => nil
-    config_param :topic,              :string,  :default => nil
-    config_param :subscription,       :string,  :default => nil
+    config_param :topic,              :string
+    config_param :subscription,       :string
     config_param :key,                :string,  :default => nil
     config_param :pull_interval,      :integer, :default => 5
     config_param :max_messages,       :integer, :default => 100
     config_param :return_immediately, :bool,    :default => true
 
-    unless method_defined?(:log)
-      define_method("log") { $log }
-    end
-
-    unless method_defined?(:router)
-      define_method("router") { Fluent::Engine }
+    config_section :parse do
+      config_set_default :@type, 'json'
     end
 
     def configure(conf)
       super
 
-      raise Fluent::ConfigError, "'topic' must be specified." unless @topic
-      raise Fluent::ConfigError, "'subscription' must be specified." unless @subscription
-
       configure_parser(conf)
     end
 
     def configure_parser(conf)
-      @parser = Fluent::TextParser.new
-      @parser.configure(conf)
+      @parser = parser_create
     end
 
     def start
@@ -44,7 +38,7 @@ def start
       topic = pubsub.topic @topic
       @client = topic.subscription @subscription
       @stop_subscribing = false
-      @subscribe_thread = Thread.new(&method(:subscribe))
+      @subscribe_thread = thread_create(:in_gcloud_pubsub_input, &method(:subscribe))
     end
 
     def shutdown
@@ -55,10 +49,6 @@ def shutdown
     end
 
     private
-    def configure_parser(conf)
-      @parser = Fluent::TextParser.new
-      @parser.configure(conf)
-    end
 
     def subscribe
       until @stop_subscribing
@@ -87,7 +77,7 @@ def subscribe
     end
 
     def parse_messages(messages)
-      es = MultiEventStream.new
+      es = Fluent::MultiEventStream.new
       messages.each do |m|
         convert_line_to_event(m.message.data, es)
       end
diff --git a/lib/fluent/plugin/out_gcloud_pubsub.rb b/lib/fluent/plugin/out_gcloud_pubsub.rb
index d80d0bf..95eb86e 100644
--- a/lib/fluent/plugin/out_gcloud_pubsub.rb
+++ b/lib/fluent/plugin/out_gcloud_pubsub.rb
@@ -1,34 +1,33 @@
 require 'gcloud'
-require 'fluent/output'
+require 'fluent/plugin/output'
 
-module Fluent
-  class GcloudPubSubOutput < BufferedOutput
+module Fluent::Plugin
+  class GcloudPubSubOutput < Output
     Fluent::Plugin.register_output('gcloud_pubsub', self)
 
-    config_set_default :buffer_type,                'lightening'
-    config_set_default :flush_interval,             1
-    config_set_default :try_flush_interval,         0.05
-    config_set_default :buffer_chunk_records_limit, 900
-    config_set_default :buffer_chunk_limit,         9437184
-    config_set_default :buffer_queue_limit,         64
+    helpers :compat_parameters
+
+    DEFAULT_BUFFER_TYPE = "memory"
 
     config_param :project,            :string,  :default => nil
-    config_param :topic,              :string,  :default => nil
+    config_param :topic,              :string
     config_param :key,                :string,  :default => nil
     config_param :autocreate_topic,   :bool,    :default => false
 
-    unless method_defined?(:log)
-      define_method("log") { $log }
-    end
-
-    unless method_defined?(:router)
-      define_method("router") { Fluent::Engine }
+    config_section :buffer do
+      config_set_default :@type, DEFAULT_BUFFER_TYPE
+      # In v0.14, buffer configurations are renamed.
+      # see: https://github.com/fluent/fluentd/blob/master/lib/fluent/plugin/buffer.rb
+      config_set_default :flush_interval,      1
+      config_set_default :try_flush_interval,  0.05
+      config_set_default :chunk_limit_records, 900
+      config_set_default :chunk_limit_size,    9437184
+      config_set_default :queue_limit_length,  64
     end
 
     def configure(conf)
+      compat_parameters_convert(conf, :buffer)
       super
-
-      raise Fluent::ConfigError, "'topic' must be specified." unless @topic
     end
 
     def start
@@ -42,6 +41,14 @@ def format(tag, time, record)
       [tag, time, record].to_msgpack
     end
 
+    def formatted_to_msgpack_binary?
+      true
+    end
+
+    def multi_workers_ready?
+      true
+    end
+
     def write(chunk)
       messages = []
 
diff --git a/test/plugin/test_in_gcloud_pubsub.rb b/test/plugin/test_in_gcloud_pubsub.rb
index c185ee9..1f9d688 100644
--- a/test/plugin/test_in_gcloud_pubsub.rb
+++ b/test/plugin/test_in_gcloud_pubsub.rb
@@ -1,5 +1,5 @@
 require_relative "../test_helper"
-
+require 'fluent/test/driver/input'
 
 class GcloudPubSubInputTest < Test::Unit::TestCase
   def setup
@@ -7,7 +7,7 @@ def setup
   end
 
   def create_driver(conf=CONFIG)
-    Fluent::Test::InputTestDriver.new(Fluent::GcloudPubSubInput).configure(conf)
+    Fluent::Test::Driver::Input.new(Fluent::Plugin::GcloudPubSubInput).configure(conf)
   end
 
   def test_configure
diff --git a/test/plugin/test_out_gcloud_pubsub.rb b/test/plugin/test_out_gcloud_pubsub.rb
index d128fd9..7d71795 100644
--- a/test/plugin/test_out_gcloud_pubsub.rb
+++ b/test/plugin/test_out_gcloud_pubsub.rb
@@ -1,5 +1,5 @@
 require_relative "../test_helper"
-
+require 'fluent/test/driver/output'
 
 class GcloudPubSubOutputTest < Test::Unit::TestCase
   DEFAULT_CONFIG = <<-EOC
@@ -16,7 +16,7 @@ def setup
   end
 
   def create_driver(conf)
-    Fluent::Test::BufferedOutputTestDriver.new(Fluent::GcloudPubSubOutput).configure(conf)
+    Fluent::Test::Driver::Output.new(Fluent::Plugin::GcloudPubSubOutput).configure(conf)
   end
 
   def test_configure
@@ -32,7 +32,7 @@ def test_configure
     assert_equal('topic-test', d.instance.topic)
     assert_equal('key-test', d.instance.key)
     assert_equal(false, d.instance.autocreate_topic)
-    assert_equal(1, d.instance.flush_interval)
+    assert_equal(1, d.instance.buffer_config.flush_interval)
   end
 
   def test_autocreate_topic
@@ -47,7 +47,9 @@ def test_autocreate_topic
 
     assert_equal(true, d.instance.autocreate_topic)
 
-    chunk = Fluent::MemoryBufferChunk.new('key', 'data')
+    tag, time, record = "tag", Fluent::Engine.now, {"a" => "b"}
+    metadata = d.instance.metadata_for_test(tag, time, record)
+    chunk = d.instance.buffer.generate_chunk(metadata)
     client = mock!
     client.topic("topic-test", autocreate: true).once
 
@@ -61,7 +63,14 @@ def test_autocreate_topic
 
   def test_re_raise_errors
     d = create_driver(DEFAULT_CONFIG)
-    chunk = Fluent::MemoryBufferChunk.new('key', 'data')
+    tag, time, record = "tag", Fluent::Engine.now, {"a" => "b"}
+    metadata = d.instance.metadata_for_test(tag, time, record)
+    chunk = d.instance.buffer.generate_chunk(metadata).tap do |c|
+      c.append([d.instance.format(tag, time, record)])
+    end
+    # For chunk#msgpack_each
+    chunk.extend Fluent::ChunkMessagePackEventStreamer
+
     client = Object.new
     def client.publish
       raise ReRaisedError