diff --git a/Casks/thunderbird-uk.rb b/Casks/thunderbird-uk.rb
index cb18334da..35a37ed5f 100644
--- a/Casks/thunderbird-uk.rb
+++ b/Casks/thunderbird-uk.rb
@@ -1,6 +1,6 @@
 cask 'thunderbird-uk' do
-  version '45.3.0'
-  sha256 '41ea1e0b5e168ce21a6eb07fe2989ff05c67312fbe8c47972b207beda91a1113'
+  version '45.4.0'
+  sha256 '7cc800300dee7298cc2b2b1636f4a5213c15b24add42d928a7306a0d5478e1e6'
 
   url "https://download.mozilla.org/?product=thunderbird-#{version}&os=osx&lang=uk"
   name 'Mozilla Thunderbird'