diff --git a/app/controllers/wechats_controller.rb b/app/controllers/wechats_controller.rb
index 619c0f586..a4797d82c 100644
--- a/app/controllers/wechats_controller.rb
+++ b/app/controllers/wechats_controller.rb
@@ -423,7 +423,7 @@ class WechatsController < ActionController::Base
         if !(session["login"] != nil && session["login"] == false)
           @path = '/login'
         end
-        session["login"] = nil
+        session.delete("login")
       else
         if params[:state] == 'myclass'
           @course_id = params[:id];