diff --git a/pkgs/applications/networking/browsers/firefox/packages.nix b/pkgs/applications/networking/browsers/firefox/packages.nix
index a0f0a1a28ef..b4e0d9c5826 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";
-    ffversion = "84.0";
+    ffversion = "84.0.1";
     src = fetchurl {
       url = "mirror://mozilla/firefox/releases/${ffversion}/source/firefox-${ffversion}.source.tar.xz";
-      sha512 = "37d5hc2wv1b6il4flgsw5g7ihw2jx3qrrmgm4cjg3lmk91q8k7908sy79z24na6529y7jxpj4m05l6yb850wnnwjhyc4c3vxqbldnba";
+      sha512 = "0sl93h7pjiznabv6865pdbal08nlqncnv3g40l02mgwbphjh5iqrr1bz14khaf58h4v1la090cj7z0gmd0c10xfrx6z7wngm152zz75";
     };
 
     meta = {