diff --git a/Casks/firefox-esr-uk.rb b/Casks/firefox-esr-uk.rb
index 990fb6add..9825d349f 100644
--- a/Casks/firefox-esr-uk.rb
+++ b/Casks/firefox-esr-uk.rb
@@ -1,6 +1,6 @@
 cask 'firefox-esr-uk' do
-  version '45.2.0'
-  sha256 '94e8d474688c5d1e084dab88e50b5568cdc675ada401adb0bd8d472c1b1bf0da'
+  version '45.3.0'
+  sha256 'caf251ad76d6431052cc12bcab699c84447045520da1042d1a826cbb27995aee'
 
   # mozilla.net was verified as official when first introduced to the cask
   url "https://download-installer.cdn.mozilla.net/pub/firefox/releases/#{version}esr/mac/uk/Firefox%20#{version}esr.dmg"