diff --git a/pkgs/applications/networking/browsers/firefox/packages/firefox-esr-128.nix b/pkgs/applications/networking/browsers/firefox/packages/firefox-esr-128.nix
index 6a6b23035891..b931700335ac 100644
--- a/pkgs/applications/networking/browsers/firefox/packages/firefox-esr-128.nix
+++ b/pkgs/applications/networking/browsers/firefox/packages/firefox-esr-128.nix
@@ -9,10 +9,10 @@
 
 buildMozillaMach rec {
   pname = "firefox";
-  version = "128.5.0esr";
+  version = "128.5.1esr";
   src = fetchurl {
     url = "mirror://mozilla/firefox/releases/${version}/source/firefox-${version}.source.tar.xz";
-    sha512 = "ff20f18f92c5e9cd1d9eaf7c38cec61bcab2dca8dd2817519b712bc1f760b5c6e290212acf3289152764e5130e01626950b7ecd9327b2c587b24a246591afd67";
+    sha512 = "476d71ff45a7178301081191d1b4c47fb21b42618f12191605f95ad48603b84a9150cb5c96f668751a43c8f6a4a43ecf337d38007d8e2b546f006faead2d66d5";
   };
 
   meta = {