diff --git a/fluentd.gemspec b/fluentd.gemspec
index cb8f1701c6..3b1a95e0e5 100644
--- a/fluentd.gemspec
+++ b/fluentd.gemspec
@@ -38,6 +38,7 @@ Gem::Specification.new do |gem|
     gem.add_runtime_dependency("win32-service", ["~> 2.3.0"])
     gem.add_runtime_dependency("win32-ipc", ["~> 0.7.0"])
     gem.add_runtime_dependency("win32-event", ["~> 0.6.3"])
+    gem.add_runtime_dependency("windows-api", ["~> 0.4.5"])
     gem.add_runtime_dependency("windows-pr", ["~> 1.2.6"])
     gem.add_runtime_dependency("certstore_c", ["~> 0.1.7"])
   end
diff --git a/lib/fluent/plugin/file_wrapper.rb b/lib/fluent/plugin/file_wrapper.rb
index ca864b0943..0ef875b14e 100644
--- a/lib/fluent/plugin/file_wrapper.rb
+++ b/lib/fluent/plugin/file_wrapper.rb
@@ -62,8 +62,9 @@ def close
 
     # To keep backward compatibility, we continue to use GetFileInformationByHandle()
     # to get file id.
-    # Node that Ruby's File.stat uses GetFileInformationByHandleEx() with FileIdInfo
-    # and returned value is different with above one.
+    # Note that Ruby's File.stat uses GetFileInformationByHandleEx() with FileIdInfo
+    # and returned value is different with above one, former one is 64 bit while
+    # later one is 128bit.
     def ino
       by_handle_file_information = '\0'*(4+8+8+8+4+4+4+4+4+4)   #72bytes