diff --git a/lib/fluent/plugin/parser_apache.rb b/lib/fluent/plugin/parser_apache.rb
index 1973f9c653..49b65dcf1e 100644
--- a/lib/fluent/plugin/parser_apache.rb
+++ b/lib/fluent/plugin/parser_apache.rb
@@ -14,7 +14,7 @@
 #    limitations under the License.
 #
 
-require 'fluent/plugin/parser'
+require 'fluent/plugin/parser_regexp'
 
 module Fluent
   module Plugin
diff --git a/lib/fluent/plugin/parser_apache_error.rb b/lib/fluent/plugin/parser_apache_error.rb
index deb68e715c..19d4e9bebf 100644
--- a/lib/fluent/plugin/parser_apache_error.rb
+++ b/lib/fluent/plugin/parser_apache_error.rb
@@ -14,7 +14,7 @@
 #    limitations under the License.
 #
 
-require 'fluent/plugin/parser'
+require 'fluent/plugin/parser_regexp'
 
 module Fluent
   module Plugin
diff --git a/lib/fluent/plugin/parser_nginx.rb b/lib/fluent/plugin/parser_nginx.rb
index 9dc7151add..8cad4ed322 100644
--- a/lib/fluent/plugin/parser_nginx.rb
+++ b/lib/fluent/plugin/parser_nginx.rb
@@ -14,7 +14,7 @@
 #    limitations under the License.
 #
 
-require 'fluent/plugin/parser'
+require 'fluent/plugin/parser_regexp'
 
 module Fluent
   module Plugin
diff --git a/lib/fluent/plugin/parser_regexp.rb b/lib/fluent/plugin/parser_regexp.rb
index cea171fad8..723d9dd707 100644
--- a/lib/fluent/plugin/parser_regexp.rb
+++ b/lib/fluent/plugin/parser_regexp.rb
@@ -1,3 +1,21 @@
+#
+# Fluentd
+#
+#    Licensed under the Apache License, Version 2.0 (the "License");
+#    you may not use this file except in compliance with the License.
+#    You may obtain a copy of the License at
+#
+#        http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS,
+#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#    See the License for the specific language governing permissions and
+#    limitations under the License.
+#
+
+require 'fluent/plugin/parser'
+
 module Fluent
   module Plugin
     class RegexpParser < Parser