diff --git a/krebs/krops.nix b/krebs/krops.nix
index aeb2413a4..c55865d54 100644
--- a/krebs/krops.nix
+++ b/krebs/krops.nix
@@ -10,8 +10,8 @@
   krebs-source = { test ? false }: rec {
     nixpkgs = if test then {
       derivation = let
-        rev = (lib.importJSON ./nixpkgs.json).rev;
-        sha256 = (lib.importJSON ./nixpkgs.json).sha256;
+        rev = (lib.importJSON ../flake.lock).nodes.nixpkgs.locked.rev;
+        sha256 = (lib.importJSON ../flake.lock).nixpkgs.locked.narHash;
       in ''
         with import (builtins.fetchTarball {
           url = "https://github.com/nixos/nixpkgs/archive/${rev}.tar.gz";
@@ -26,8 +26,8 @@
       '';
     } else {
       git = {
-        ref = (lib.importJSON ./nixpkgs.json).rev;
-        url = https://github.com/NixOS/nixpkgs;
+        ref = (lib.importJSON ../flake.lock).nodes.nixpkgs.locked.rev;
+        url = "https://github.com/NixOS/nixpkgs";
         shallow = true;
       };
     };
diff --git a/krebs/nixpkgs.json b/krebs/nixpkgs.json
deleted file mode 100644
index 0b6021ed0..000000000
--- a/krebs/nixpkgs.json
+++ /dev/null
@@ -1,12 +0,0 @@
-{
-  "url": "https://github.com/NixOS/nixpkgs",
-  "rev": "9075cba53e86dc318d159aee55dc9a7c9a4829c1",
-  "date": "2023-09-02T08:28:47+02:00",
-  "path": "/nix/store/605bv7zssv38j0ii8rbnxkv1m0f0b53p-nixpkgs",
-  "sha256": "0kymzp32d31c0hny2b2f7zfn49nzrxlm963xbm4v0axka6abym36",
-  "hash": "sha256-ZlS/lFGzK7BJXX2YVGnP3yZi3T9OLOEtBCyMJsb91U8=",
-  "fetchLFS": false,
-  "fetchSubmodules": false,
-  "deepClone": false,
-  "leaveDotGit": false
-}
diff --git a/krebs/update-nixpkgs.sh b/krebs/update-nixpkgs.sh
deleted file mode 100755
index 465548f44..000000000
--- a/krebs/update-nixpkgs.sh
+++ /dev/null
@@ -1,9 +0,0 @@
-#!/bin/sh
-dir=$(dirname $0)
-oldrev=$(cat $dir/nixpkgs.json | jq -r .rev | sed 's/\(.\{7\}\).*/\1/')
-nix-shell -p nix-prefetch-git --run 'nix-prefetch-git \
-  --url https://github.com/NixOS/nixpkgs \
-  --rev refs/heads/nixos-23.05' \
-> $dir/nixpkgs.json
-newrev=$(cat $dir/nixpkgs.json | jq -r .rev | sed 's/\(.\{7\}\).*/\1/')
-git commit $dir/nixpkgs.json -m "nixpkgs: $oldrev -> $newrev"