diff --git a/pkgs/os-specific/linux/kernel/linux-testing-bcachefs.nix b/pkgs/os-specific/linux/kernel/linux-testing-bcachefs.nix
index fa5729baf73..48f1a22475f 100644
--- a/pkgs/os-specific/linux/kernel/linux-testing-bcachefs.nix
+++ b/pkgs/os-specific/linux/kernel/linux-testing-bcachefs.nix
@@ -1,24 +1,33 @@
-{ lib, buildPackages, fetchFromGitHub, fetchpatch, perl, buildLinux, ... } @ args:
+{ lib
+, fetchpatch
+, kernel
+, date ? "2021-07-08"
+, commit ? "3693b2ca83ff9eda49660b31299d2bebe3a1075f"
+, diffHash ? "1sfq3vwc2kxa761s292f2cqrm0vvqvkdx6drpyn5yaxwnapwidcw"
+, kernelPatches # must always be defined in bcachefs' all-packages.nix entry because it's also a top-level attribute supplied by callPackage
+, argsOverride ? {}
+, ...
+} @ args:
 
-buildLinux (args // {
-  # NOTE: bcachefs-tools should be updated simultaneously to preserve compatibility
-  version = "5.13.0-2021.10.01";
-  modDirVersion = "5.13.0";
+# NOTE: bcachefs-tools should be updated simultaneously to preserve compatibility
+(kernel.override ( args // {
+  argsOverride = {
+    version = "${kernel.version}-bcachefs-unstable-${date}";
+    extraMeta = {
+      branch = "master";
+      maintainers = with lib.maintainers; [ davidak chiiruno ];
+      platforms = [ "x86_64-linux" ];
+    };
+  } // argsOverride;
 
-  src = fetchFromGitHub {
-    owner = "koverstreet";
-    repo = "bcachefs";
-    rev = "4114ced1db465b8f4e7f4d6a78aa11416a9ab5d9";
-    sha256 = "sha256-viFC3HHIcjUTDPvloSKKsz9PuSLyvxfYnrtkVUB79mQ=";
-  };
+  kernelPatches = [ {
+      name = "bcachefs-${commit}";
+      patch = fetchpatch {
+        name = "bcachefs-${commit}.diff";
+        url = "https://evilpiepirate.org/git/bcachefs.git/rawdiff/?id=${commit}&id2=v${lib.versions.majorMinor kernel.version}";
+        sha256 = diffHash;
+      };
+      extraConfig = "BCACHEFS_FS m";
+    } ] ++ kernelPatches;
 
-  extraConfig = "BCACHEFS_FS m";
-
-  extraMeta = {
-    branch = "master";
-    hydraPlatforms = []; # Should the testing kernels ever be built on Hydra?
-    maintainers = with lib.maintainers; [ davidak chiiruno ];
-    platforms = [ "x86_64-linux" ];
-  };
-
-} // (args.argsOverride or {}))
+})).overrideAttrs ({ meta ? {}, ... }: { meta = meta // { broken = true; }; })
diff --git a/pkgs/tools/filesystems/bcachefs-tools/default.nix b/pkgs/tools/filesystems/bcachefs-tools/default.nix
index bdb7e55b5cf..be7a42e19e9 100644
--- a/pkgs/tools/filesystems/bcachefs-tools/default.nix
+++ b/pkgs/tools/filesystems/bcachefs-tools/default.nix
@@ -22,21 +22,20 @@
 
 stdenv.mkDerivation {
   pname = "bcachefs-tools";
-  version = "unstable-2021-10-01";
+  version = "unstable-2021-07-08";
 
   src = fetchFromGitHub {
     owner = "koverstreet";
     repo = "bcachefs-tools";
-    rev = "37850436dd7dfbe67738749c4d4a2506ffff1ec3";
-    sha256 = "040vgxrimahmfs9rhlggfwg0bzl7h9j2ksx3563rh63asjwlhnhi";
+    rev = "050d5f7bcf08bd02f5077a1c5559f352fa449e1e";
+    sha256 = "15bl9ni0ckmvs5d7hi6v26z690rrmkb7dx00skn6gwq87ffz3imw";
   };
 
   postPatch = ''
     substituteInPlace Makefile \
       --replace "pytest-3" "pytest --verbose" \
       --replace "INITRAMFS_DIR=/etc/initramfs-tools" \
-                "INITRAMFS_DIR=${placeholder "out"}/etc/initramfs-tools" \
-      --replace "doc/macro2rst.py" "python3 doc/macro2rst.py"
+                "INITRAMFS_DIR=${placeholder "out"}/etc/initramfs-tools"
   '';
 
   nativeBuildInputs = [ pkg-config docutils ];