diff --git a/Casks/waterfox.rb b/Casks/waterfox.rb
index 1d773f371504b..01d31edd79bea 100644
--- a/Casks/waterfox.rb
+++ b/Casks/waterfox.rb
@@ -1,6 +1,6 @@
 cask :v1 => 'waterfox' do
-  version '39.0'
-  sha256 'ba25c4c3a422b2727d5d47a1369fb26b3c66d9c03967fdd22076e27fff982134'
+  version '40.0.2'
+  sha256 '49720ec39019cc7991531677014bbd140062fb72f0d5dbd963f7f14b75da37b6'
 
   # cloudfront.net is the official download host per the vendor homepage
   url "https://d1th2p59px32bw.cloudfront.net/releases/osx64/installer/Waterfox%20#{version}%20Setup.dmg"