diff --git a/.github/workflows/nix-ci.yml b/.github/workflows/nix-ci.yml
index ee95678ab..e25bc0e4b 100644
--- a/.github/workflows/nix-ci.yml
+++ b/.github/workflows/nix-ci.yml
@@ -25,4 +25,4 @@ jobs:
             nix_path: nixpkgs=channel:${{ matrix.os == 'macos-latest' && 'nixpkgs-24.05-darwin' || 'nixos-24.05' }}
 
         - name: Run tests
-          run: nix-shell --run "hatch run testing:test"
+          run: nix-shell --run "hatch run testing:test -- ./src/ ./test/"
diff --git a/shell.nix b/shell.nix
index 033840927..8bf5303c6 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,12 +1,15 @@
 { pkgs ? import <nixpkgs> {} }:
 let
-  unstable = import <nixos-unstable> {};
+  unstable = import (fetchTarball https://nixos.org/channels/nixos-unstable/nixexprs.tar.xz) {};
 in
 pkgs.mkShell {
   buildInputs = [
     pkgs.glibcLocales
     pkgs.libiconv  # for macos
 
+    pkgs.ps
+    pkgs.libsodium
+
     pkgs.postgresql
     pkgs.redis
     pkgs.kubo