diff --git a/pkgs/applications/networking/browsers/firefox/packages.nix b/pkgs/applications/networking/browsers/firefox/packages.nix
index cdaf63179512..d52ec29abcf8 100644
--- a/pkgs/applications/networking/browsers/firefox/packages.nix
+++ b/pkgs/applications/networking/browsers/firefox/packages.nix
@@ -7,10 +7,10 @@ in
 rec {
   firefox = common rec {
     pname = "firefox";
-    version = "99.0";
+    version = "99.0.1";
     src = fetchurl {
       url = "mirror://mozilla/firefox/releases/${version}/source/firefox-${version}.source.tar.xz";
-      sha512 = "08f6d5a668140c4275aba6df463ed3af596043dfe5f27573583afbc1e9f6b27ebca79a52ce2c9598261c631b400b5378744e9e70f51ef9c4098b419e9904aa7c";
+      sha512 = "0006b773ef1057a6e0b959d4f39849ad4a79272b38d565da98062b9aaf0effd2b729349c1f9fa10fccf7d2462d2c536b02c167ae6ad4556d6e519c6d22c25a7f";
     };
 
     meta = {