diff --git a/lib/fluent/plugin/in_redis_slowlog.rb b/lib/fluent/plugin/in_redis_slowlog.rb
index 6a18e44..3944dd7 100644
--- a/lib/fluent/plugin/in_redis_slowlog.rb
+++ b/lib/fluent/plugin/in_redis_slowlog.rb
@@ -1,3 +1,4 @@
+require 'fluent/input'
 class Fluent::Redis_SlowlogInput < Fluent::Input
   Fluent::Plugin.register_input('redis_slowlog', self)
 
diff --git a/test/helper.rb b/test/helper.rb
index 326a2d5..2507ffa 100644
--- a/test/helper.rb
+++ b/test/helper.rb
@@ -1,5 +1,6 @@
 require 'rubygems'
 require 'bundler'
+require 'fluent/input'
 begin
   Bundler.setup(:default, :development)
 rescue Bundler::BundlerError => e