diff --git a/AUTHORS b/AUTHORS
index 612a1712..45f10ceb 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -1 +1,2 @@
 FURUHASHI Sadayuki <frsyuki _at_ gmail.com>
+MASAHIRO Nakagawa <repeatedly _at_ gmail.com>
diff --git a/fluent-plugin-s3.gemspec b/fluent-plugin-s3.gemspec
index f36c5a23..7f53445b 100644
--- a/fluent-plugin-s3.gemspec
+++ b/fluent-plugin-s3.gemspec
@@ -7,7 +7,7 @@ Gem::Specification.new do |gem|
   gem.homepage    = "https://github.com/fluent/fluent-plugin-s3"
   gem.summary     = gem.description
   gem.version     = File.read("VERSION").strip
-  gem.authors     = ["Sadayuki Furuhashi"]
+  gem.authors     = ["Sadayuki Furuhashi", "Masahiro Nakagawa"]
   gem.email       = "frsyuki@gmail.com"
   gem.has_rdoc    = false
   #gem.platform    = Gem::Platform::RUBY