diff --git a/lib/fluent/env.rb b/lib/fluent/env.rb
index d79ad7df3b..2916ff669d 100644
--- a/lib/fluent/env.rb
+++ b/lib/fluent/env.rb
@@ -20,4 +20,5 @@ module Fluent
   DEFAULT_SOCKET_PATH = ENV['FLUENT_SOCKET'] || '/var/run/fluent/fluent.sock'
   DEFAULT_LISTEN_PORT = 24224
   DEFAULT_FILE_PERMISSION = 0644
+  DEFAULT_DIR_PERMISSION = 0755
 end
diff --git a/lib/fluent/plugin/buf_file.rb b/lib/fluent/plugin/buf_file.rb
index 342a41a872..e60fe8aa0a 100644
--- a/lib/fluent/plugin/buf_file.rb
+++ b/lib/fluent/plugin/buf_file.rb
@@ -114,7 +114,7 @@ def configure(conf)
     end
 
     def start
-      FileUtils.mkdir_p File.dirname(@buffer_path_prefix + "path")
+      FileUtils.mkdir_p File.dirname(@buffer_path_prefix + "path"), :mode => DEFAULT_DIR_PERMISSION
       super
     end
 
diff --git a/lib/fluent/plugin/out_file.rb b/lib/fluent/plugin/out_file.rb
index 1774bda177..92d0c134c2 100644
--- a/lib/fluent/plugin/out_file.rb
+++ b/lib/fluent/plugin/out_file.rb
@@ -73,7 +73,7 @@ def format(tag, time, record)
 
     def write(chunk)
       path = generate_path(chunk)
-      FileUtils.mkdir_p File.dirname(path)
+      FileUtils.mkdir_p File.dirname(path), :mode => DEFAULT_DIR_PERMISSION
 
       case @compress
       when nil