diff --git a/lib/action_controller/wechat_responder.rb b/lib/action_controller/wechat_responder.rb
index 3de629b1..649f2a27 100644
--- a/lib/action_controller/wechat_responder.rb
+++ b/lib/action_controller/wechat_responder.rb
@@ -48,12 +48,12 @@ def load_controller_wechat(account, opts = {})
     end
   end
 
-  if defined? Base
-    class << Base
+  if defined? API
+    class << API
       include WechatResponder
     end
-  elsif defined? API
-    class << API
+  elsif defined? Base
+    class << Base
       include WechatResponder
     end
   end