diff --git a/nongnu/packages/mozilla.scm b/nongnu/packages/mozilla.scm
index d6bc572..9103c0a 100644
--- a/nongnu/packages/mozilla.scm
+++ b/nongnu/packages/mozilla.scm
@@ -559,10 +559,14 @@ MOZ_ENABLE_WAYLAND=1 exec ~a $@\n"
        (uri (string-append "https://archive.mozilla.org/pub/firefox/releases/"
                            version "/source/firefox-" version ".source.tar.xz"))
        (patches
-        (list (search-path
-               (map (cut string-append <> "/nongnu/packages/patches")
-                    %load-path)
-               "firefox-restore-desktop-files.patch")))
+        (map (lambda (patch)
+               (search-path
+                (map (cut string-append <> "/nongnu/packages/patches")
+                     %load-path)
+                patch))
+             '("firefox-restore-desktop-files.patch"
+               "firefox-esr-compare-paths.patch"
+               "firefox-use-system-wide-dir.patch")))
        (sha256
         (base32 "06ya18ma1gndci0aygz75hidn3kwa1kji78g8smh7fq0091aad7i"))))
     (arguments
diff --git a/nongnu/packages/patches/firefox-use-system-wide-dir.patch b/nongnu/packages/patches/firefox-use-system-wide-dir.patch
new file mode 100644
index 0000000..564f12f
--- /dev/null
+++ b/nongnu/packages/patches/firefox-use-system-wide-dir.patch
@@ -0,0 +1,37 @@
+Replace "/usr/lib/mozilla" (the system-wide directory for extensions and
+native manifests) with "$ICECAT_SYSTEM_DIR".
+
+diff --git a/toolkit/xre/nsXREDirProvider.cpp b/toolkit/xre/nsXREDirProvider.cpp
+index e3be04e70c..a3501c4f44 100644
+--- a/toolkit/xre/nsXREDirProvider.cpp
++++ b/toolkit/xre/nsXREDirProvider.cpp
+@@ -280,24 +280,11 @@ nsresult nsXREDirProvider::GetBackgroundTasksProfilesRootDir(
+ static nsresult GetSystemParentDirectory(nsIFile** aFile) {
+   nsresult rv;
+   nsCOMPtr<nsIFile> localDir;
+-#  if defined(XP_MACOSX)
+-  rv = GetOSXFolderType(kOnSystemDisk, kApplicationSupportFolderType,
+-                        getter_AddRefs(localDir));
+-  if (NS_SUCCEEDED(rv)) {
+-    rv = localDir->AppendNative("Mozilla"_ns);
+-  }
+-#  else
+-  constexpr auto dirname =
+-#    ifdef HAVE_USR_LIB64_DIR
+-      "/usr/lib64/mozilla"_ns
+-#    elif defined(__OpenBSD__) || defined(__FreeBSD__)
+-      "/usr/local/lib/mozilla"_ns
+-#    else
+-      "/usr/lib/mozilla"_ns
+-#    endif
+-      ;
+-  rv = NS_NewNativeLocalFile(dirname, getter_AddRefs(localDir));
+-#  endif
++  const char* systemParentDir = getenv("ICECAT_SYSTEM_DIR");
++  if (!systemParentDir || !*systemParentDir) return NS_ERROR_FAILURE;
++
++  rv = NS_NewNativeLocalFile(nsDependentCString(systemParentDir),
++                             getter_AddRefs(localDir));
+ 
+   if (NS_SUCCEEDED(rv)) {
+     localDir.forget(aFile);