diff --git a/app/controllers/documents_controller.rb b/app/controllers/documents_controller.rb
index 8a9d514..4310b7d 100644
--- a/app/controllers/documents_controller.rb
+++ b/app/controllers/documents_controller.rb
@@ -17,7 +17,7 @@ class DocumentsController < ApplicationController
 
   def show
     @subjects = Cdao::Subject.all
-    @doctrines = @document.doctrines.sort_by { |doctrine| @doctrines.sort_by { |doctrine| [-doctrine.jurisprudences.first.year, -doctrine.jurisprudences.first.docdate] }
+    @doctrines = @document.doctrines.sort_by { |doctrine| [-doctrine.jurisprudences.first.year, -doctrine.jurisprudences.first.docdate.strftime("%Y-%m-%d")] }
 
     where = { enabled: true, state: "published" }
     @cited_in_documents = @document.class.citing_docs_of(@document, where)