diff --git a/pkgs/applications/networking/browsers/firefox/packages.nix b/pkgs/applications/networking/browsers/firefox/packages.nix
index cd5b7742c6d6..dba371b22e1d 100644
--- a/pkgs/applications/networking/browsers/firefox/packages.nix
+++ b/pkgs/applications/networking/browsers/firefox/packages.nix
@@ -3,10 +3,10 @@
 {
   firefox = buildMozillaMach rec {
     pname = "firefox";
-    version = "120.0.1";
+    version = "121.0";
     src = fetchurl {
       url = "mirror://mozilla/firefox/releases/${version}/source/firefox-${version}.source.tar.xz";
-      sha512 = "dd0e3eb234d58c39431d1f100834ef4bcc8cfb89ff471a37b948eda4dd3874b63b1979cda39a0db0dd3b4a579b5f09a7d2d1f39d26fd9f2b8d5635e4b8738b6c";
+      sha512 = "52e9e21ce825c4e58f09fd2c7347f1ac4efbca47e119136a712f0d4ee80c769ef80a43bad74a4c88cd377f804f5780b07f7af5b779f3fb5d244fa095e6b3b18a";
     };
 
     extraPatches = [