diff --git a/pkgs/applications/networking/browsers/firefox/packages.nix b/pkgs/applications/networking/browsers/firefox/packages.nix
index e34120de9c00..10249aea4ee9 100644
--- a/pkgs/applications/networking/browsers/firefox/packages.nix
+++ b/pkgs/applications/networking/browsers/firefox/packages.nix
@@ -1,11 +1,7 @@
-{ stdenv, lib, callPackage, fetchurl, fetchpatch, nixosTests }:
-
-let
-  common = opts: callPackage (import ./common.nix opts) {};
-in
+{ stdenv, lib, callPackage, fetchurl, fetchpatch, nixosTests, buildMozillaMach }:
 
 rec {
-  firefox = common rec {
+  firefox = buildMozillaMach rec {
     pname = "firefox";
     version = "100.0";
     src = fetchurl {
@@ -30,7 +26,7 @@ rec {
     };
   };
 
-  firefox-esr-91 = common rec {
+  firefox-esr-91 = buildMozillaMach rec {
     pname = "firefox-esr";
     version = "91.9.0esr";
     src = fetchurl {
@@ -54,30 +50,4 @@ rec {
       versionSuffix = "esr";
     };
   };
-
-  librewolf =
-  let
-    librewolf-src = callPackage ./librewolf { };
-  in
-  (common rec {
-    pname = "librewolf";
-    binaryName = "librewolf";
-    version = librewolf-src.packageVersion;
-    src = librewolf-src.firefox;
-    inherit (librewolf-src) extraConfigureFlags extraPostPatch extraPassthru;
-
-    meta = {
-      description = "A fork of Firefox, focused on privacy, security and freedom";
-      homepage = "https://librewolf.net/";
-      maintainers = with lib.maintainers; [ squalus ];
-      inherit (firefox.meta) platforms badPlatforms broken maxSilent license;
-    };
-    updateScript = callPackage ./librewolf/update.nix {
-      attrPath = "librewolf-unwrapped";
-    };
-  }).override {
-    crashreporterSupport = false;
-    enableOfficialBranding = false;
-    pgoSupport = false; # Profiling gets stuck and doesn't terminate.
-  };
 }
diff --git a/pkgs/applications/networking/browsers/librewolf/default.nix b/pkgs/applications/networking/browsers/librewolf/default.nix
new file mode 100644
index 000000000000..8f3100de970d
--- /dev/null
+++ b/pkgs/applications/networking/browsers/librewolf/default.nix
@@ -0,0 +1,31 @@
+{ stdenv, lib, callPackage, buildMozillaMach }:
+
+let
+  librewolf-src = callPackage ./librewolf.nix { };
+in
+(buildMozillaMach rec {
+  pname = "librewolf";
+  binaryName = "librewolf";
+  version = librewolf-src.packageVersion;
+  src = librewolf-src.firefox;
+  inherit (librewolf-src) extraConfigureFlags extraPostPatch extraPassthru;
+
+  meta = {
+    description = "A fork of Firefox, focused on privacy, security and freedom";
+    homepage = "https://librewolf.net/";
+    maintainers = with lib.maintainers; [ squalus ];
+    platforms = lib.platforms.unix;
+    badPlatforms = lib.platforms.darwin;
+    broken = stdenv.buildPlatform.is32bit; # since Firefox 60, build on 32-bit platforms fails with "out of memory".
+                                           # not in `badPlatforms` because cross-compilation on 64-bit machine might work.
+    maxSilent = 14400; # 4h, double the default of 7200s (c.f. #129212, #129115)
+    license = lib.licenses.mpl20;
+  };
+  updateScript = callPackage ./update.nix {
+    attrPath = "librewolf-unwrapped";
+  };
+}).override {
+  crashreporterSupport = false;
+  enableOfficialBranding = false;
+  pgoSupport = false; # Profiling gets stuck and doesn't terminate.
+}
diff --git a/pkgs/applications/networking/browsers/firefox/librewolf/default.nix b/pkgs/applications/networking/browsers/librewolf/librewolf.nix
similarity index 98%
rename from pkgs/applications/networking/browsers/firefox/librewolf/default.nix
rename to pkgs/applications/networking/browsers/librewolf/librewolf.nix
index 10b65e8825c2..68ed776e91c9 100644
--- a/pkgs/applications/networking/browsers/firefox/librewolf/default.nix
+++ b/pkgs/applications/networking/browsers/librewolf/librewolf.nix
@@ -1,4 +1,4 @@
-{ callPackage, git }:
+{ callPackage }:
 let
   src = callPackage ./src.nix { };
 in
diff --git a/pkgs/applications/networking/browsers/firefox/librewolf/src.json b/pkgs/applications/networking/browsers/librewolf/src.json
similarity index 100%
rename from pkgs/applications/networking/browsers/firefox/librewolf/src.json
rename to pkgs/applications/networking/browsers/librewolf/src.json
diff --git a/pkgs/applications/networking/browsers/firefox/librewolf/src.nix b/pkgs/applications/networking/browsers/librewolf/src.nix
similarity index 100%
rename from pkgs/applications/networking/browsers/firefox/librewolf/src.nix
rename to pkgs/applications/networking/browsers/librewolf/src.nix
diff --git a/pkgs/applications/networking/browsers/firefox/librewolf/update.nix b/pkgs/applications/networking/browsers/librewolf/update.nix
similarity index 96%
rename from pkgs/applications/networking/browsers/firefox/librewolf/update.nix
rename to pkgs/applications/networking/browsers/librewolf/update.nix
index 5cb5c6168f73..b8bc64afafe0 100644
--- a/pkgs/applications/networking/browsers/firefox/librewolf/update.nix
+++ b/pkgs/applications/networking/browsers/librewolf/update.nix
@@ -20,7 +20,7 @@ writeScript "update-librewolf" ''
   latestTag=$(curl https://gitlab.com/api/v4/projects/librewolf-community%2Fbrowser%2Fsource/repository/tags?per_page=1 | jq -r .[0].name)
   echo "latestTag=$latestTag"
 
-  srcJson=pkgs/applications/networking/browsers/firefox/librewolf/src.json
+  srcJson=pkgs/applications/networking/browsers/librewolf/src.json
   localRev=$(jq -r .source.rev < $srcJson)
   echo "localRev=$localRev"
 
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index c82544ce55bf..6707930edd47 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -26404,11 +26404,13 @@ with pkgs;
 
   filezilla = callPackage ../applications/networking/ftp/filezilla { };
 
-  firefoxPackages = recurseIntoAttrs (callPackage ../applications/networking/browsers/firefox/packages.nix {
-    callPackage = newScope {
+  buildMozillaMach =
+    let callPackage = newScope {
       inherit (rustPackages) cargo rustc;
     };
-  });
+    in opts: callPackage (import ../applications/networking/browsers/firefox/common.nix opts) {};
+
+  firefoxPackages = recurseIntoAttrs (callPackage ../applications/networking/browsers/firefox/packages.nix {});
 
   firefox-unwrapped = firefoxPackages.firefox;
   firefox-esr-91-unwrapped = firefoxPackages.firefox-esr-91;
@@ -26453,7 +26455,7 @@ with pkgs;
     desktopName = "Firefox DevEdition";
   };
 
-  librewolf-unwrapped = firefoxPackages.librewolf;
+  librewolf-unwrapped = callPackage ../applications/networking/browsers/librewolf {};
 
   librewolf = wrapFirefox librewolf-unwrapped {
     inherit (librewolf-unwrapped) extraPrefsFiles extraPoliciesFiles;