diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 8e94939b..528155b9 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -32,49 +32,35 @@ jobs:
           - ubuntu-latest
         python-version:
           - "3.9"
-          - "3.10"
-          - "3.11"
           - "3.12"
+          - "3.13"
         include:
           - os: windows-latest
             python-version: "3.9"
           - os: macos-13
             python-version: "3.9"
-          - os: macos-14
+          - os: macos-latest
             python-version: "3.12"  # old versions not supported
     name: Check Python ${{ matrix.python-version }} ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-
       - name: Setup Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
 
-      - name: Get pip cache dir
-        id: pip-cache
-        run: |
-          echo "::set-output name=dir::$(pip cache dir)"
-      - name: pip cache
-        uses: actions/cache@v4.1.2
-        with:
-          path: ${{ steps.pip-cache.outputs.dir }}
-          key: ${{ runner.os }}-pip-${{ hashFiles('**/setup.cfg') }}-pip-${{ hashFiles('**/setup.py') }}-pip-${{ hashFiles('**/pyproject.toml') }}
-          restore-keys: |
-            ${{ runner.os }}-pip-
-
       - name: Install package
         run: |
-          python -m pip install --upgrade pip
-          python -m pip install -e .[test] pytest-xdist   # for multiprocessing
+          pip install uv
+          uv pip install --system -e .[test] pytest-xdist   # for multiprocessing, -e needed for pathes etc.
 
       - name: Test package
         run: python -m pytest --doctest-modules --cov=hepstats --cov-report=xml -n auto
 
       - name: Upload coverage to Codecov
-        if: matrix.python-version == '3.12' && matrix.os == 'ubuntu-latest'
+        if: matrix.python-version == '3.9' && matrix.os == 'ubuntu-latest'
         uses: codecov/codecov-action@v4
         with:
           token: ${{ secrets.CODECOV_TOKEN }}  # technically not needed, but prevents failures: https://community.codecov.com/t/upload-issues-unable-to-locate-build-via-github-actions-api/3954
@@ -106,13 +92,16 @@ jobs:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: actions/setup-python@v5
+
+      - name: Setup Python 3.9
+        uses: actions/setup-python@v5
         with:
-          python-version: "3.11"
+          python-version: 3.9
+
       - name: Install dependencies
         run: |
-          pip install -U -q -e .[docs]
-          pip list
+          pip install uv
+          uv pip install --system -e .[docs]
       - name: build docs
         run: |
           sphinx-build -b html docs docs/_build/html
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index fed9f1e8..a44b54e7 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -19,16 +19,16 @@ repos:
       - id: requirements-txt-fixer
       - id: debug-statements
       - id: end-of-file-fixer
-  - repo: https://github.com/mgedmin/check-manifest
-    rev: "0.50"
-    hooks:
-      - id: check-manifest
-        args:
-          - --update
-          - --no-build-isolation
-        additional_dependencies:
-          - hatchling
-          - hatch-vcs
+#  - repo: https://github.com/mgedmin/check-manifest
+#    rev: "0.50"
+#    hooks:
+#      - id: check-manifest
+#        args:
+#          - --update
+#          - --no-build-isolation
+#        additional_dependencies:
+#          - hatchling
+#          - hatch-vcs
 
   - repo: https://github.com/pre-commit/mirrors-mypy
     rev: v1.12.0
@@ -60,7 +60,7 @@ repos:
     rev: v2.7.0
     hooks:
       - id: setup-cfg-fmt
-        args: [ --max-py-version=3.12, --include-version-classifiers ]
+        args: [ --max-py-version=3.13, --include-version-classifiers ]
 
   # Notebook formatting
   - repo: https://github.com/nbQA-dev/nbQA
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 1d10f316..9d2d11ba 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -4,6 +4,8 @@ Changelog
 main
 **************
 
+* Add support for Python 3.13
+
 Version 0.8.1
 **************
 
diff --git a/MANIFEST.in b/MANIFEST.in
deleted file mode 100644
index 3f22b4ff..00000000
--- a/MANIFEST.in
+++ /dev/null
@@ -1,24 +0,0 @@
-graft docs
-prune docs/_build
-graft src
-graft tests
-graft notebooks
-
-global-exclude .env*
-global-exclude .git*
-global-exclude .pytest_cache
-global-exclude .DS_Store
-global-exclude .ipynb_checkpoints
-global-exclude *-checkpoint.ipynb
-global-exclude *-checkpoint.py
-global-exclude *.py[co]
-global-exclude __pycache__
-
-prune .ci
-prune .github
-
-include README.md pyproject.toml setup.py setup.cfg
-include *.yaml
-include *.yml
-recursive-include LICENSES *
-include CHANGELOG.rst
diff --git a/pyproject.toml b/pyproject.toml
index af71286b..c80c96a2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -68,7 +68,8 @@ test = [
     "pytest",
     "pytest-cov",
     "pytest-runner",
-    "zfit>=0.20.0",
+    "zfit>=0.20.0;python_version<'3.13'",
+#    'hepstats[zfit];python_version<"3.13"',  # not working, why?
 ]
 zfit = ["zfit>=0.20.0"]
 
diff --git a/tests/conftest.py b/tests/conftest.py
index 81440b93..f1980a58 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -32,7 +32,11 @@ def data_gen():
 # TODO: manually ported, use pre-made: https://github.com/zfit/zfit-development/issues/73
 @pytest.fixture(autouse=True)
 def _setup_teardown():
-    import zfit
+    try:
+        import zfit
+    except ImportError:
+        yield
+        return
 
     old_chunksize = zfit.run.chunking.max_n_points
     old_active = zfit.run.chunking.active
diff --git a/tests/hypotests/test_basetest.py b/tests/hypotests/test_basetest.py
index 2b28a8fc..b2053f74 100644
--- a/tests/hypotests/test_basetest.py
+++ b/tests/hypotests/test_basetest.py
@@ -1,6 +1,6 @@
 import pytest
 import numpy as np
-import zfit
+zfit = pytest.importorskip("zfit")
 from zfit.loss import UnbinnedNLL
 from zfit.minimize import Minuit
 
@@ -9,6 +9,7 @@
 from hepstats.hypotests.parameters import POI, POIarray
 
 
+
 def create_loss():
     obs = zfit.Space("x", limits=(0.1, 2.0))
     data = zfit.data.Data.from_numpy(obs=obs, array=np.random.normal(1.2, 0.1, 10000))
diff --git a/tests/hypotests/test_calculators.py b/tests/hypotests/test_calculators.py
index 111bad55..35bd25a7 100644
--- a/tests/hypotests/test_calculators.py
+++ b/tests/hypotests/test_calculators.py
@@ -2,7 +2,7 @@
 
 import numpy as np
 import pytest
-import zfit
+zfit = pytest.importorskip("zfit")
 from zfit.loss import UnbinnedNLL
 from zfit.minimize import Minuit
 
diff --git a/tests/hypotests/test_confidence_intervals.py b/tests/hypotests/test_confidence_intervals.py
index e99d3d14..e2c02b3c 100644
--- a/tests/hypotests/test_confidence_intervals.py
+++ b/tests/hypotests/test_confidence_intervals.py
@@ -1,6 +1,6 @@
 import pytest
 import numpy as np
-import zfit
+zfit = pytest.importorskip("zfit")
 import os
 from zfit.loss import UnbinnedNLL
 from zfit.minimize import Minuit
diff --git a/tests/hypotests/test_discovery.py b/tests/hypotests/test_discovery.py
index 75eb861e..39c2f171 100644
--- a/tests/hypotests/test_discovery.py
+++ b/tests/hypotests/test_discovery.py
@@ -2,7 +2,7 @@
 
 import numpy as np
 import pytest
-import zfit
+zfit = pytest.importorskip("zfit")
 from zfit.loss import UnbinnedNLL
 from zfit.minimize import Minuit
 
diff --git a/tests/hypotests/test_parameters.py b/tests/hypotests/test_parameters.py
index 20af9974..b24aa884 100644
--- a/tests/hypotests/test_parameters.py
+++ b/tests/hypotests/test_parameters.py
@@ -1,7 +1,7 @@
 #!/usr/bin/python
 import pytest
 import numpy as np
-import zfit
+zfit = pytest.importorskip("zfit")
 
 from hepstats.hypotests.parameters import POI, POIarray
 
diff --git a/tests/hypotests/test_toysutils.py b/tests/hypotests/test_toysutils.py
index 21b82140..6fd0b8b7 100644
--- a/tests/hypotests/test_toysutils.py
+++ b/tests/hypotests/test_toysutils.py
@@ -1,6 +1,6 @@
 import pytest
 import numpy as np
-import zfit
+zfit = pytest.importorskip("zfit")
 import os
 from zfit.loss import ExtendedUnbinnedNLL, UnbinnedNLL
 from zfit.minimize import Minuit
diff --git a/tests/hypotests/test_upperlimit.py b/tests/hypotests/test_upperlimit.py
index 4865ecc6..45755206 100644
--- a/tests/hypotests/test_upperlimit.py
+++ b/tests/hypotests/test_upperlimit.py
@@ -1,6 +1,7 @@
 import pytest
 import numpy as np
 import os
+zfit = pytest.importorskip("zfit")
 from zfit.minimize import Minuit
 
 import hepstats
diff --git a/tests/modeling/test_bayesianblocks.py b/tests/modeling/test_bayesianblocks.py
index 2346cdd6..3cb23fa3 100644
--- a/tests/modeling/test_bayesianblocks.py
+++ b/tests/modeling/test_bayesianblocks.py
@@ -1,9 +1,11 @@
-import os
+from pathlib import Path
+
 import numpy as np
+
 import hepstats
 from hepstats.modeling import bayesian_blocks
 
-answer_dir = os.path.dirname(hepstats.__file__) + "/../../tests/modeling/data"
+answer_dir = Path(__file__).parent / "data"
 
 
 def test_bayesian_blocks(cmdopt, data_gen):
@@ -12,10 +14,10 @@ def test_bayesian_blocks(cmdopt, data_gen):
     be3 = bayesian_blocks(data_gen[0], weights=data_gen[2])
 
     if cmdopt == "generate":
-        with open(answer_dir + "/answers_bayesian_blocks.npz", "wb") as f:
+        with open(answer_dir / "answers_bayesian_blocks.npz", "wb") as f:
             np.savez(f, be1=be1, be2=be2, be3=be3)
     elif cmdopt == "test":
-        answers = np.load(answer_dir + "/answers_bayesian_blocks.npz")
+        answers = np.load(answer_dir / "answers_bayesian_blocks.npz")
         assert np.all(be1 == answers["be1"])
         assert np.all(be2 == answers["be2"])
         assert np.all(be3 == answers["be3"])
diff --git a/tests/splots/test_splots.py b/tests/splots/test_splots.py
index 459429ec..051b89dc 100644
--- a/tests/splots/test_splots.py
+++ b/tests/splots/test_splots.py
@@ -2,7 +2,7 @@
 import pytest
 from scipy.stats import ks_2samp
 
-import zfit
+zfit = pytest.importorskip("zfit")
 from zfit.loss import ExtendedUnbinnedNLL
 from zfit.minimize import Minuit