diff --git a/lib/fluent/output.rb b/lib/fluent/output.rb
index 65f0445040..5589dcdf65 100644
--- a/lib/fluent/output.rb
+++ b/lib/fluent/output.rb
@@ -20,50 +20,11 @@
 require 'fluent/configurable'
 require 'fluent/engine'
 require 'fluent/log'
+require 'fluent/output_chain'
 require 'fluent/plugin'
 require 'fluent/timezone'
 
 module Fluent
-  class OutputChain
-    def initialize(array, tag, es, chain=NullOutputChain.instance)
-      @array = array
-      @tag = tag
-      @es = es
-      @offset = 0
-      @chain = chain
-    end
-
-    def next
-      if @array.length <= @offset
-        return @chain.next
-      end
-      @offset += 1
-      result = @array[@offset-1].emit(@tag, @es, self)
-      result
-    end
-  end
-
-  class CopyOutputChain < OutputChain
-    def next
-      if @array.length <= @offset
-        return @chain.next
-      end
-      @offset += 1
-      es = @array.length > @offset ? @es.dup : @es
-      result = @array[@offset-1].emit(@tag, es, self)
-      result
-    end
-  end
-
-  class NullOutputChain
-    require 'singleton'
-    include Singleton
-
-    def next
-    end
-  end
-
-
   class Output
     include Configurable
     include PluginId
@@ -622,4 +583,3 @@ class MultiOutput < Output
     #end
   end
 end
-
diff --git a/lib/fluent/output_chain.rb b/lib/fluent/output_chain.rb
new file mode 100644
index 0000000000..3883d62d8e
--- /dev/null
+++ b/lib/fluent/output_chain.rb
@@ -0,0 +1,57 @@
+#
+# 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.
+#
+
+# OutputChain will be removed since v0.14.
+module Fluent
+  class OutputChain
+    def initialize(array, tag, es, chain=NullOutputChain.instance)
+      @array = array
+      @tag = tag
+      @es = es
+      @offset = 0
+      @chain = chain
+    end
+
+    def next
+      if @array.length <= @offset
+        return @chain.next
+      end
+      @offset += 1
+      result = @array[@offset-1].emit(@tag, @es, self)
+      result
+    end
+  end
+
+  class CopyOutputChain < OutputChain
+    def next
+      if @array.length <= @offset
+        return @chain.next
+      end
+      @offset += 1
+      es = @array.length > @offset ? @es.dup : @es
+      result = @array[@offset-1].emit(@tag, es, self)
+      result
+    end
+  end
+
+  class NullOutputChain
+    require 'singleton'
+    include Singleton
+
+    def next
+    end
+  end
+end
diff --git a/test/test_output.rb b/test/test_output.rb
index dda1ca3c5d..21ba75c5ff 100644
--- a/test/test_output.rb
+++ b/test/test_output.rb
@@ -1,6 +1,7 @@
 require_relative 'helper'
 require 'fluent/test'
 require 'fluent/output'
+require 'fluent/output_chain'
 require 'timecop'
 require 'flexmock'