diff --git a/Casks/thunderbird-ja.rb b/Casks/thunderbird-ja.rb
index f6620d0d5..d555ea799 100644
--- a/Casks/thunderbird-ja.rb
+++ b/Casks/thunderbird-ja.rb
@@ -1,8 +1,8 @@
 class ThunderbirdJa < Cask
-  version '24.2.0'
-  sha256 'a3e4d03924ee555865b90bb95f8043811e15bfd20358e5b265b5b1cfc4812b7d'
+  version '31.1.1'
+  sha256 'aa5da47afcc4f71e40f86b94c6033d86d707690a80a8610e1a5f9c09a5ca4629'
 
-  url 'http://download-installer.cdn.mozilla.net/pub/thunderbird/releases/24.2.0/mac/ja-JP-mac/Thunderbird%2024.2.0.dmg'
+  url "https://download.mozilla.org/?product=thunderbird-#{version}&os=osx&lang=ja-JP-mac"
   homepage 'http://www.mozilla.jp/thunderbird/'
 
   app 'Thunderbird.app'