diff --git a/.github/workflows/cicd.yml b/.github/workflows/cicd.yml
index a7909a3..7c66141 100644
--- a/.github/workflows/cicd.yml
+++ b/.github/workflows/cicd.yml
@@ -126,4 +126,4 @@ jobs:
               # remove repository key to set the default to pypi (not test.pypi.org) 
               repository-url: https://test.pypi.org/legacy/
               user: __token__
-              password: ${{ secrets.PYPI_API_TOKEN }}
\ No newline at end of file
+              password: ${{ secrets.PYPI_API_TOKEN }}
diff --git a/README.md b/README.md
index 8f39f58..e222061 100644
--- a/README.md
+++ b/README.md
@@ -124,7 +124,7 @@ docs\conf.py:
 Install package so that new code is picked up in a restared python interpreter:
 
 ```
-pip install -e .
+pip install -e ".[dev]"
 ```
 
 ## TestPyPI
@@ -143,4 +143,4 @@ The documentation is build using readthedocs automatically. See
 [project on Readthedocs](https://readthedocs.org/projects/rasmussenlab-python-package/).
 
 - make sure to enable build from PRs in the settings (advanded settings)
-- checkout configuration file: [`.readthedocs.yaml`](.readthedocs.yaml)
\ No newline at end of file
+- checkout configuration file: [`.readthedocs.yaml`](.readthedocs.yaml)
diff --git a/docs/conf.py b/docs/conf.py
index 4b85843..cad48da 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -57,9 +57,7 @@
 nb_merge_streams = True
 
 # https://myst-nb.readthedocs.io/en/latest/authoring/custom-formats.html#write-custom-formats
-nb_custom_formats = {
-    ".py": ["jupytext.reads", {"fmt": "py:percent"}]
-}
+nb_custom_formats = {".py": ["jupytext.reads", {"fmt": "py:percent"}]}
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ["_templates"]
@@ -67,8 +65,13 @@
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
 # This pattern also affects html_static_path and html_extra_path.
-exclude_patterns = ["_build", "Thumbs.db",
-                    ".DS_Store", "jupyter_execute", "conf.py",]
+exclude_patterns = [
+    "_build",
+    "Thumbs.db",
+    ".DS_Store",
+    "jupyter_execute",
+    "conf.py",
+]
 
 
 # Intersphinx options
diff --git a/pyproject.toml b/pyproject.toml
index 1ca1dc2..d3ed587 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 [project]
 authors = [
-  {name = "Jakob Nybo Nissen", email = "jakobnybonissen@gmail.com"},
-  {name = "Henry Webel", email = "henry.webel@sund.ku.dk"},
+  { name = "Jakob Nybo Nissen", email = "jakobnybonissen@gmail.com" },
+  { name = "Henry Webel", email = "henry.webel@sund.ku.dk" },
 ]
 description = "A small example package"
 name = "rasmussenlab-mockup"
@@ -31,10 +31,11 @@ docs = [
   "sphinx-new-tab-link!=0.2.2",
   "jupytext",
 ]
+dev = ["black", "ruff", "pytest"]
 
 # Configure the Ruff linter: Ignore error number 501
 [tool.ruff]
-ignore = ["E501"]
+lint.ignore = ["E501"]
 
 [build-system]
 build-backend = "setuptools.build_meta"