diff --git a/Casks/tower1.rb b/Casks/tower1.rb
index 707c46649..88a917ed5 100644
--- a/Casks/tower1.rb
+++ b/Casks/tower1.rb
@@ -3,7 +3,8 @@ class Tower1 < Cask
   sha256 :no_check
 
   url 'http://www.git-tower.com/download-v1'
-  appcast 'https://macapps.fournova.com/tower1-1060/updates.xml'
+  appcast 'https://macapps.fournova.com/tower1-1060/updates.xml',
+          :sha256 => '0a053ca1cf31f5dd6512a4528a4d793a4993c2e180002c4967511a6dc9bfbf87'
   homepage 'http://www.git-tower.com/'
   license :unknown