diff --git a/lib/zhong.rb b/lib/zhong.rb
index af0b667..1c5ce8f 100644
--- a/lib/zhong.rb
+++ b/lib/zhong.rb
@@ -4,6 +4,7 @@
 require "msgpack"
 require "redis"
 require "suo"
+require "active_support"
 require "active_support/time"
 
 require "zhong/version"