diff --git a/.github/workflows/bats.yml b/.github/workflows/bats.yml
index 5864827..5262715 100644
--- a/.github/workflows/bats.yml
+++ b/.github/workflows/bats.yml
@@ -4,13 +4,18 @@
 
 on: [push, pull_request]
 
+name: "Tests"
+permissions: {}
+
 jobs:
    bats:
      runs-on: ubuntu-latest
+     container: debian:latest
      steps:
        - uses: actions/checkout@v3
        - name: install bats
-         uses: brokenpip3/setup-bats-libs@1.5.2
+         run: |
+          apt-get update && apt-get install -y bats jq zstd
        - name: run bats
          run: |
            bats -x -r tests
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..0f71834
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,26 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1703148052,
+        "narHash": "sha256-D2UaI7fxUrdBzSBwd7BVC9VvEl45XosNXc0A2HE7WlY=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "71807aee99a47a8bf1d606f858244bbd6803da23",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.lock.license b/flake.lock.license
new file mode 100644
index 0000000..cd213ca
--- /dev/null
+++ b/flake.lock.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: Stefan Tatschner
+
+SPDX-License-Identifier: CC0-1.0
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..2f18901
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,24 @@
+# SPDX-FileCopyrightText: Stefan Tatschner
+#
+# SPDX-License-Identifier: CC0-1.0
+
+{
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs";
+  };
+
+  outputs = { self, nixpkgs }:
+    with import nixpkgs { system = "x86_64-linux"; };
+    let pkgs = nixpkgs.legacyPackages.x86_64-linux;
+    in {
+      devShell.x86_64-linux = pkgs.mkShell {
+        buildInputs = with pkgs; [ 
+          bats
+        ];
+        shellHook = ''
+          LD_LIBRARY_PATH=${pkgs.lib.makeLibraryPath [stdenv.cc.cc]}
+        '';
+      };
+      formatter.x86_64-linux = pkgs.nixpkgs-fmt;
+    };
+}
diff --git a/tests/0001-invocation.bats b/tests/0001-invocation.bats
index c6fdf84..ba23af0 100644
--- a/tests/0001-invocation.bats
+++ b/tests/0001-invocation.bats
@@ -11,35 +11,29 @@ setup() {
 }
 
 @test "invoke penrun without parameters" {
-    local tmpdir
-    tmpdir="$(mktemp -d)"
-    (
-        cd "$tmpdir"
-        penrun -c /dev/null ls -lah
-        if [[ ! -d "ls" ]]; then
-            echo "output directory is missing"
-            return 1
-        fi
-
-        mapfile -t meta < "ls/LATEST/META.json"
-        for line in "${meta[@]}"; do
-            local cmd
-            local exit_code
-            if [[ "$line" =~ EXIT:(.+) ]]; then
-                exit_code="${BASH_REMATCH[1]}"
-                if ((exit_code != 0)); then
-                    return 1
-                fi
-            fi
-            if [[ "$line" =~ COMMAND:(.+)\s$ ]]; then
-                cmd="${BASH_REMATCH[1]}"
-                if [[ "$cmd" != "ls -lah" ]]; then
-                    echo "$cmd"
-                    return 1
-                fi
-            fi
-        done
-
-        rm -rf "$tmpdir"
-    )
+    cd "$BATS_TEST_TMPDIR"
+
+    mkdir foo
+
+    run penrun -c /dev/null ls -lah
+
+    if (( $status != "0" )); then
+        echo "penrun failed"
+        return 1
+    fi
+
+    if [[ ! -d "ls" ]]; then
+        echo "output directory is missing"
+        return 1
+    fi
+
+    if (( "$(jq ".exit_code" < ls/LATEST/META.json)" != "0" )); then
+        echo "exit_code in META != 0"
+        return 1
+    fi
+
+    if [[ "$(jq -r '.command | join(" ")' < ls/LATEST/META.json)" != "ls -lah" ]]; then
+        echo "command != ls -lah"
+        return 1
+    fi
 }