diff --git a/default.nix b/default.nix
deleted file mode 100644
index 4f9e1c59b8..0000000000
--- a/default.nix
+++ /dev/null
@@ -1,11 +0,0 @@
-{ pkgs ? import <nixpkgs> {} }:
-let
-in
-  pkgs.mkShell {
-    buildInputs = [
-      pkgs.platformio
-      pkgs.python3
-      # optional: needed as a programmer i.e. for esp32
-      pkgs.avrdude
-    ];
-}
diff --git a/shell.nix b/shell.nix
new file mode 100644
index 0000000000..d437668adb
--- /dev/null
+++ b/shell.nix
@@ -0,0 +1,23 @@
+let
+  pkgs = import <nixpkgs> {
+    config = {
+      # Allow unfree adafruit-nrfutil, see https://github.com/adafruit/Adafruit_nRF52_nrfutil/issues/41
+      allowUnfreePredicate = pkg: pkg.pname or null == "adafruit-nrfutil";
+
+      # Ignore CVE-2024-23342 for python-ecdsa, see https://github.com/tlsfuzzer/python-ecdsa/issues/330
+      permittedInsecurePackages = [
+        "python3.13-ecdsa-0.19.1"
+      ];
+    };
+  };
+in
+pkgs.mkShellNoCC {
+  packages = with pkgs; [
+    platformio
+    python3
+    # optional: needed as a programmer i.e. for esp32
+    avrdude
+    # optional: programmer for some nrf52 devices
+    adafruit-nrfutil
+  ];
+}