diff --git a/lib/fluent/command/cat.rb b/lib/fluent/command/cat.rb
index 49f4aaa469..8ec8a5e2c1 100644
--- a/lib/fluent/command/cat.rb
+++ b/lib/fluent/command/cat.rb
@@ -288,6 +288,8 @@ def abort_message(time, record)
   end
 
 when 'msgpack'
+  require 'fluent/engine'
+
   begin
     u = Fluent::Engine.msgpack_factory.unpacker($stdin)
     u.each {|record|
diff --git a/lib/fluent/engine.rb b/lib/fluent/engine.rb
index 6952495478..05883ffbe4 100644
--- a/lib/fluent/engine.rb
+++ b/lib/fluent/engine.rb
@@ -17,6 +17,7 @@
 module Fluent
   require 'fluent/event_router'
   require 'fluent/root_agent'
+  require 'fluent/time'
 
   class EngineClass
     def initialize