diff --git a/justfile b/justfile
index 6b54cb2..58f25cf 100644
--- a/justfile
+++ b/justfile
@@ -44,14 +44,14 @@ exports-deps:
 
 # Run tests, ARGS are passed-through to pytest
 test *ARGS:
-  {{ uv }} run pytest tests.py -m "not final" {{ ARGS }}
+  {{ uv }} run pytest -m "not final" {{ ARGS }}
 
 alltests *ARGS:
-  {{ uv }} run pytest tests.py {{ ARGS }}
+  {{ uv }} run pytest {{ ARGS }}
 
 # run tests and create coverage reports
 coverage:
-  {{ uv }} run pytest tests.py -m "not final" --cov=src/ --cov-report term --cov-report xml --cov-report html --cov-config {{ pyproject }}
+  {{ uv }} run pytest -m "not final" --cov=src/ --cov-report term --cov-report xml --cov-report html --cov-config {{ pyproject }}
 
 # lint python, markdown, wheel file names, prek config
 lint:
diff --git a/pyproject.toml b/pyproject.toml
index fde6187..3971eb9 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -48,6 +48,7 @@ dev = [
   "pytest>=9.0.1",
   "pytest-asyncio>=1.3.0",
   "pytest-cov>=7.0.0",
+  "pytest-sugar>=1.1.1",
   "pytest-textual-snapshot>=1.0.0",
   "textual-dev>=1.8.0",
   "twine>=6.2.0",
@@ -59,11 +60,17 @@ build-backend = "uv_build"
 
 [tool.coverage.run]
 branch = true
-omit = ["tests.py"]
+omit = ["tests/"]
 source_dirs = ["src/"]
 
-[tool.pytest]
 # custom marks are created in conftest.py
+[tool.pytest]
+python_files = ["*_test.py", "test_*.py", "tests.py"]
+strict_config = true
+strict_markers = true
+strict_parametrization_ids = false
+strict_xfail = true
+testpaths = ["testing/"]
 asyncio_mode = "auto"
 
 [tool.ruff]
diff --git a/conftest.py b/testing/conftest.py
similarity index 100%
rename from conftest.py
rename to testing/conftest.py
diff --git a/tests.py b/testing/tests.py
similarity index 99%
rename from tests.py
rename to testing/tests.py
index 55b40b8..0620a27 100644
--- a/tests.py
+++ b/testing/tests.py
@@ -31,7 +31,6 @@ empty_teilchen_data = {
     "number": 1,
 }
 
-
 def TC(**kwargs) -> TeilchenCreate | None:
     """TC = TeilchenCreate