diff --git a/pkgs/tools/package-management/nix/default.nix b/pkgs/tools/package-management/nix/default.nix
index a5fb98d7557..b08b33f816e 100644
--- a/pkgs/tools/package-management/nix/default.nix
+++ b/pkgs/tools/package-management/nix/default.nix
@@ -14,7 +14,7 @@ common =
   , pkg-config, boehmgc, libsodium, brotli, boost, editline, nlohmann_json
   , autoreconfHook, autoconf-archive, bison, flex
   , jq, libarchive, libcpuid
-  , lowdown, mdbook
+  , lowdown-0-9, mdbook
   # Used by tests
   , gtest
   , busybox-sandbox-shell
@@ -45,7 +45,7 @@ common =
           [ autoreconfHook
             autoconf-archive
             bison flex
-            (lib.getBin lowdown) mdbook
+            (lib.getBin lowdown-0-9) mdbook
             jq
            ];
 
@@ -55,7 +55,7 @@ common =
         ]
         ++ lib.optionals stdenv.isDarwin [ Security ]
         ++ lib.optional (stdenv.isLinux || stdenv.isDarwin) libsodium
-        ++ lib.optionals is24 [ libarchive gtest lowdown ]
+        ++ lib.optionals is24 [ libarchive gtest lowdown-0-9 ]
         ++ lib.optional (is24 && stdenv.isx86_64) libcpuid
         ++ lib.optional withLibseccomp libseccomp
         ++ lib.optional withAWS
@@ -228,13 +228,13 @@ in rec {
   nixUnstable = lib.lowPrio (callPackage common rec {
     pname = "nix";
     version = "2.4${suffix}";
-    suffix = "pre20210922_${lib.substring 0 7 src.rev}";
+    suffix = "pre20211006_${lib.substring 0 7 src.rev}";
 
     src = fetchFromGitHub {
       owner = "NixOS";
       repo = "nix";
-      rev = "bcd73ebf60bb9ba6cb09f8df4366d5474c16e4a4";
-      sha256 = "sha256-wRbz8c22tlRn2/va/yOoLJijdJn+JJqLRDPRlifaEEA=";
+      rev = "53e479428958b39a126ce15de85d7397fdcfe2e1";
+      sha256 = "18mm3f0n964msj5bha6wpnwckg5lwjwdm6r7frrwdj75v10jiyb7";
     };
 
     boehmgc = boehmgc_nixUnstable;
diff --git a/pkgs/tools/typesetting/lowdown/0.9.x.nix b/pkgs/tools/typesetting/lowdown/0.9.x.nix
new file mode 100644
index 00000000000..1e1b4aad181
--- /dev/null
+++ b/pkgs/tools/typesetting/lowdown/0.9.x.nix
@@ -0,0 +1,12 @@
+# Latest version of lowdown, backported from unstable separately due to breaking changes
+{ lowdown
+, fetchurl
+}:
+
+lowdown.overrideAttrs (_: rec {
+  version = "0.9.0";
+  src = fetchurl {
+    url = "https://kristaps.bsd.lv/lowdown/snapshots/lowdown-${version}.tar.gz";
+    sha512 = "0v3l70c9mal67i369bk3q67qyn07kmclybcd5lj5ibdrrccq1jzsxn2sy39ziy77in7cygcb1lgf9vzacx9rscw94i6259fy0dpnf0h";
+  };
+})
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 3470d482a8c..cd7b710e3b1 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -2858,6 +2858,8 @@ in
 
   lowdown = callPackage ../tools/typesetting/lowdown { };
 
+  lowdown-0-9 = lowPrio (callPackage ../tools/typesetting/lowdown/0.9.x.nix { });
+
   numatop = callPackage ../os-specific/linux/numatop { };
 
   numworks-udev-rules = callPackage ../os-specific/linux/numworks-udev-rules { };