diff --git a/pkgs/applications/networking/browsers/firefox/common.nix b/pkgs/applications/networking/browsers/firefox/common.nix
index 670cbb34260..207f069f86a 100644
--- a/pkgs/applications/networking/browsers/firefox/common.nix
+++ b/pkgs/applications/networking/browsers/firefox/common.nix
@@ -11,7 +11,7 @@
 , hunspell, libevent, libstartup_notification, libvpx
 , icu, libpng, jemalloc, glib
 , autoconf213, which, gnused, cargo, rustc, llvmPackages
-, rust-cbindgen, nodejs, nasm
+, rust-cbindgen, nodejs, nasm, fetchpatch
 , debugBuild ? false
 
 ### optionals
@@ -94,6 +94,15 @@ let
 
   browserPatches = [
     ./env_var_for_system_dir.patch
+  ] ++ lib.optionals (stdenv.isAarch64 && lib.versionAtLeast ffversion "66") [
+    (fetchpatch {
+      url = "https://raw.githubusercontent.com/archlinuxarm/PKGBUILDs/09c7fa0dc1d87922e3b464c0fa084df1227fca79/extra/firefox/arm.patch";
+      sha256 = "1vbpih23imhv5r3g21m3m541z08n9n9j1nvmqax76bmyhn7mxp32";
+    })
+    (fetchpatch {
+      url = "https://raw.githubusercontent.com/archlinuxarm/PKGBUILDs/09c7fa0dc1d87922e3b464c0fa084df1227fca79/extra/firefox/build-arm-libopus.patch";
+      sha256 = "1zg56v3lc346fkzcjjx21vjip2s9hb2xw4pvza1dsfdnhsnzppfp";
+    })
   ] ++ patches;
 
 in