diff --git a/default.nix b/default.nix
index f9190fb..05aa0d8 100644
--- a/default.nix
+++ b/default.nix
@@ -19,6 +19,7 @@ pkgs.python3Packages.buildPythonPackage rec {
     cryptography
   ];
 
+  # nativeCheckInputs = [ pkgs.python3Packages.pytestCheckHook ];
   pythonImportsCheck = [ "smtprd_ng" ];
 
   meta = {
diff --git a/devenv.nix b/devenv.nix
index 72b3f9c..4618f7b 100644
--- a/devenv.nix
+++ b/devenv.nix
@@ -5,20 +5,20 @@
 , ...
 }:
 
+let
+  req = pkgs.concatText "req" [
+    ./requirements.txt
+    ./requirements-dev.txt
+  ];
+in
+
 {
-  # https://devenv.sh/basics/
-  # env.GREET = "devenv";
-
   # https://devenv.sh/packages/
-  packages = [ pkgs.file pkgs.swig4 pkgs.openssl ];
-
-  # https://devenv.sh/scripts/
-  # scripts.hello.exec = "echo hello from $GREET";
-
-  # enterShell = ''
-  #   hello
-  #   git --version
-  # '';
+  packages = [
+    pkgs.file
+    pkgs.swig4
+    pkgs.openssl
+  ];
 
   # https://devenv.sh/tests/
   # enterTest = ''
@@ -35,7 +35,7 @@
     enable = true;
     venv = {
       enable = true;
-      requirements = ./requirements.txt;
+      requirements = builtins.readFile req;
     };
   };
 
@@ -54,7 +54,6 @@
     pylint.enable = true;
     detect-private-keys.enable = true;
 
-
   };
 
   # https://devenv.sh/processes/
diff --git a/pyproject.toml b/pyproject.toml
index d0e1a42..18bd41e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,14 +7,11 @@ name = "smtprd-ng"
 version = "0.0.1"
 description = "SMTP forwarding relay daemon with signing and encryption"
 authors = [{ name = "Florian Brandes", email = "dev@mail.flo-the.dev" }]
-classifiers = ["License :: OSI Approved :: GNU Affero General Public License v3" ]
-license = { text = "MIT License" }
-dependencies = [
-    "aiosmtpd",
-    "aiosmtplib",
-    "M2Crypto",
-    "cryptography",
+classifiers = [
+    "License :: OSI Approved :: GNU Affero General Public License v3",
 ]
+license = { text = "MIT License" }
+dependencies = ["aiosmtpd", "aiosmtplib", "M2Crypto", "cryptography"]
 requires-python = ">=3.10"
 keywords = ["smtp", "smime"]
 
@@ -23,3 +20,6 @@ smtprd-ng = "smtprd_ng.smtprd:main"
 
 [project.urls]
 Repository = "https://app.radicle.xyz/nodes/seed.radicle.garden/rad:z3gWc1qgaeZaoGwL4WTstLNoqjayM"
+
+[project.optional-dependencies]
+tests = ["pytest", "pytest-cov"]
diff --git a/requirements-dev.txt b/requirements-dev.txt
new file mode 100644
index 0000000..cffeec6
--- /dev/null
+++ b/requirements-dev.txt
@@ -0,0 +1,2 @@
+pytest
+pytest-cov
\ No newline at end of file
diff --git a/requirements.txt b/requirements.txt
index b997fad..d396786 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
 aiosmtpd
 aiosmtplib
 M2Crypto
-cryptography
\ No newline at end of file
+cryptography