diff --git a/.gitattributes b/.gitattributes
index df3d57a0..45307422 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1 +1 @@
-pyscal/_version.py export-subst
+src/pyscal/_version.py export-subst
diff --git a/.github/workflows/codecov.yml b/.github/workflows/codecov.yml
index 0cb850a4..c64b90d4 100644
--- a/.github/workflows/codecov.yml
+++ b/.github/workflows/codecov.yml
@@ -19,7 +19,7 @@ jobs:
     - uses: actions/checkout@main
 
     - name: Setup Python
-      uses: actions/setup-python@main
+      uses: actions/setup-python@v5
       with:
         python-version: 3.11
 
diff --git a/.github/workflows/pyscal.yml b/.github/workflows/pyscal.yml
index a92a620c..4ed70d9b 100644
--- a/.github/workflows/pyscal.yml
+++ b/.github/workflows/pyscal.yml
@@ -44,7 +44,7 @@ jobs:
           fetch-depth: 0
 
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
 
@@ -71,7 +71,7 @@ jobs:
       - name: Check typing with mypy
         if: ${{ always() }}
         run: |
-          mypy ./pyscal
+          mypy src/pyscal
 
       - name: Run tests
         if: ${{ always() }}
diff --git a/.gitignore b/.gitignore
index 748e435c..70af5986 100644
--- a/.gitignore
+++ b/.gitignore
@@ -110,4 +110,4 @@ env*/
 
 # mypy
 .mypy_cache/
-pyscal/version.py
+src/pyscal/version.py
diff --git a/CONTRIBUTING.rst b/CONTRIBUTING.rst
index e6e11731..d669ef9d 100644
--- a/CONTRIBUTING.rst
+++ b/CONTRIBUTING.rst
@@ -55,7 +55,7 @@ Now you can make your changes locally.
   
         ruff check .
         ruff format .
-        mypy ./pyscal
+        mypy src/pyscal
         pytest -n auto
   
 8. Commit your changes and push your branch to GitHub:
diff --git a/docs/make_plots.py b/docs/make_plots.py
index 842536a1..d6084e45 100644
--- a/docs/make_plots.py
+++ b/docs/make_plots.py
@@ -2,7 +2,6 @@
 from pathlib import Path
 
 import matplotlib.pyplot as plt
-
 from pyscal import GasOil, GasWater, WaterOil
 
 IMG_DIR = Path(__file__).absolute().parent / "images"
diff --git a/pyproject.toml b/pyproject.toml
index 93248743..3c4a273a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,11 +7,8 @@ requires = [
 
 build-backend = "setuptools.build_meta"
 
-[tool.setuptools]
-packages = ["pyscal"]
-
 [tool.setuptools_scm]
-write_to = "pyscal/version.py"
+write_to = "src/pyscal/version.py"
 
 [project]
 name = "pyscal"
@@ -79,7 +76,7 @@ pyscal = "pyscal.pyscalcli:main"
 
 
 [tool.ruff]
-select=[
+lint.select=[
     "E",
     "F",
     "I",
@@ -96,7 +93,7 @@ select=[
 
 line-length = 88
 
-ignore = ["E741"]
+lint.ignore = ["E741"]
 
 [[tool.mypy.overrides]]
 module = ["numpy.*", "pyscal.version", "pandas.*", "matplotlib.*", "scipy.*", "xlrd.*", "openpyxl.*"
diff --git a/pyscal/__init__.py b/src/pyscal/__init__.py
similarity index 100%
rename from pyscal/__init__.py
rename to src/pyscal/__init__.py
diff --git a/pyscal/constants.py b/src/pyscal/constants.py
similarity index 100%
rename from pyscal/constants.py
rename to src/pyscal/constants.py
diff --git a/pyscal/factory.py b/src/pyscal/factory.py
similarity index 100%
rename from pyscal/factory.py
rename to src/pyscal/factory.py
diff --git a/pyscal/gasoil.py b/src/pyscal/gasoil.py
similarity index 100%
rename from pyscal/gasoil.py
rename to src/pyscal/gasoil.py
diff --git a/pyscal/gaswater.py b/src/pyscal/gaswater.py
similarity index 100%
rename from pyscal/gaswater.py
rename to src/pyscal/gaswater.py
diff --git a/pyscal/plotting.py b/src/pyscal/plotting.py
similarity index 100%
rename from pyscal/plotting.py
rename to src/pyscal/plotting.py
diff --git a/pyscal/pyscalcli.py b/src/pyscal/pyscalcli.py
similarity index 100%
rename from pyscal/pyscalcli.py
rename to src/pyscal/pyscalcli.py
diff --git a/pyscal/pyscallist.py b/src/pyscal/pyscallist.py
similarity index 100%
rename from pyscal/pyscallist.py
rename to src/pyscal/pyscallist.py
diff --git a/pyscal/scalrecommendation.py b/src/pyscal/scalrecommendation.py
similarity index 100%
rename from pyscal/scalrecommendation.py
rename to src/pyscal/scalrecommendation.py
diff --git a/pyscal/utils/__init__.py b/src/pyscal/utils/__init__.py
similarity index 100%
rename from pyscal/utils/__init__.py
rename to src/pyscal/utils/__init__.py
diff --git a/pyscal/utils/capillarypressure.py b/src/pyscal/utils/capillarypressure.py
similarity index 100%
rename from pyscal/utils/capillarypressure.py
rename to src/pyscal/utils/capillarypressure.py
diff --git a/pyscal/utils/interpolation.py b/src/pyscal/utils/interpolation.py
similarity index 100%
rename from pyscal/utils/interpolation.py
rename to src/pyscal/utils/interpolation.py
diff --git a/pyscal/utils/monotonicity.py b/src/pyscal/utils/monotonicity.py
similarity index 100%
rename from pyscal/utils/monotonicity.py
rename to src/pyscal/utils/monotonicity.py
diff --git a/pyscal/utils/relperm.py b/src/pyscal/utils/relperm.py
similarity index 100%
rename from pyscal/utils/relperm.py
rename to src/pyscal/utils/relperm.py
diff --git a/pyscal/utils/string.py b/src/pyscal/utils/string.py
similarity index 100%
rename from pyscal/utils/string.py
rename to src/pyscal/utils/string.py
diff --git a/pyscal/utils/testing.py b/src/pyscal/utils/testing.py
similarity index 100%
rename from pyscal/utils/testing.py
rename to src/pyscal/utils/testing.py
diff --git a/pyscal/wateroil.py b/src/pyscal/wateroil.py
similarity index 100%
rename from pyscal/wateroil.py
rename to src/pyscal/wateroil.py
diff --git a/pyscal/wateroilgas.py b/src/pyscal/wateroilgas.py
similarity index 100%
rename from pyscal/wateroilgas.py
rename to src/pyscal/wateroilgas.py
diff --git a/tests/test_estimateendpoints.py b/tests/test_estimateendpoints.py
index c833917c..5aaa003f 100644
--- a/tests/test_estimateendpoints.py
+++ b/tests/test_estimateendpoints.py
@@ -3,7 +3,6 @@
 import hypothesis.strategies as st
 import numpy as np
 from hypothesis import given
-
 from pyscal import GasOil, WaterOil
 from pyscal.constants import EPSILON as epsilon
 
diff --git a/tests/test_factory.py b/tests/test_factory.py
index b77eef8d..bdc5fed8 100644
--- a/tests/test_factory.py
+++ b/tests/test_factory.py
@@ -5,7 +5,6 @@
 import numpy as np
 import pandas as pd
 import pytest
-
 from pyscal import (
     GasOil,
     GasWater,
diff --git a/tests/test_fromtable.py b/tests/test_fromtable.py
index b9b3f8b7..07b16fd6 100644
--- a/tests/test_fromtable.py
+++ b/tests/test_fromtable.py
@@ -5,7 +5,6 @@
 import pandas as pd
 import pytest
 from hypothesis import given
-
 from pyscal import GasOil, WaterOil, WaterOilGas
 from pyscal.utils.testing import check_table, float_df_checker
 
diff --git a/tests/test_gasoil.py b/tests/test_gasoil.py
index bbf9130b..89f432a8 100644
--- a/tests/test_gasoil.py
+++ b/tests/test_gasoil.py
@@ -9,7 +9,6 @@
 import pandas as pd
 import pytest
 from hypothesis import given
-
 from pyscal import GasOil
 from pyscal.constants import MAX_EXPONENT_KR, SWINTEGERS
 from pyscal.utils.relperm import truncate_zeroness
diff --git a/tests/test_gaswater.py b/tests/test_gaswater.py
index 902be7bb..f5bde8de 100644
--- a/tests/test_gaswater.py
+++ b/tests/test_gaswater.py
@@ -8,7 +8,6 @@
 import numpy as np
 import pytest
 from hypothesis import given
-
 from pyscal import GasWater
 from pyscal.constants import SWINTEGERS
 from pyscal.utils.testing import (
diff --git a/tests/test_interactive_plots.py b/tests/test_interactive_plots.py
index e0785623..aee26e38 100644
--- a/tests/test_interactive_plots.py
+++ b/tests/test_interactive_plots.py
@@ -9,7 +9,6 @@
 import numpy as np
 import pytest
 from matplotlib import pyplot
-
 from pyscal import GasOil, GasWater, PyscalFactory, WaterOil, utils
 
 from .test_scalrecommendation import BASE_SAMPLE_LET, HIGH_SAMPLE_LET, LOW_SAMPLE_LET
diff --git a/tests/test_logging.py b/tests/test_logging.py
index f8465034..4784ef92 100644
--- a/tests/test_logging.py
+++ b/tests/test_logging.py
@@ -2,9 +2,8 @@
 import sys
 from pathlib import Path
 
-import pytest
-
 import pyscal
+import pytest
 from pyscal import pyscalcli
 
 
diff --git a/tests/test_plotting.py b/tests/test_plotting.py
index 2500b5da..947b73cc 100644
--- a/tests/test_plotting.py
+++ b/tests/test_plotting.py
@@ -4,7 +4,6 @@
 
 import matplotlib.pyplot as plt
 import pytest
-
 from pyscal import GasOil, GasWater, PyscalList, WaterOil, WaterOilGas, plotting
 
 
diff --git a/tests/test_pyscalcli.py b/tests/test_pyscalcli.py
index aeb2eea5..f9d833fb 100644
--- a/tests/test_pyscalcli.py
+++ b/tests/test_pyscalcli.py
@@ -8,7 +8,6 @@
 
 import pandas as pd
 import pytest
-
 from pyscal import pyscalcli
 from pyscal.utils.testing import sat_table_str_ok
 
diff --git a/tests/test_pyscallist.py b/tests/test_pyscallist.py
index b4f2fe0e..a6a93e64 100644
--- a/tests/test_pyscallist.py
+++ b/tests/test_pyscallist.py
@@ -5,7 +5,6 @@
 import numpy as np
 import pandas as pd
 import pytest
-
 from pyscal import (
     GasOil,
     GasWater,
diff --git a/tests/test_scalrecommendation.py b/tests/test_scalrecommendation.py
index f3963f64..f98cf6c7 100644
--- a/tests/test_scalrecommendation.py
+++ b/tests/test_scalrecommendation.py
@@ -4,7 +4,6 @@
 import pandas as pd
 import pytest
 from hypothesis import given
-
 from pyscal import GasWater, PyscalFactory, SCALrecommendation, WaterOil, WaterOilGas
 from pyscal.factory import slicedict
 from pyscal.utils.testing import check_table, sat_table_str_ok, slow_hypothesis
diff --git a/tests/test_slgof.py b/tests/test_slgof.py
index 3b7e3b85..9cb84524 100644
--- a/tests/test_slgof.py
+++ b/tests/test_slgof.py
@@ -4,7 +4,6 @@
 import numpy as np
 import pytest
 from hypothesis import given
-
 from pyscal import GasOil, WaterOilGas
 from pyscal.constants import EPSILON, SWINTEGERS
 from pyscal.utils.testing import sat_table_str_ok
diff --git a/tests/test_utils_capillarypressure.py b/tests/test_utils_capillarypressure.py
index 17684d61..24abdbda 100644
--- a/tests/test_utils_capillarypressure.py
+++ b/tests/test_utils_capillarypressure.py
@@ -5,7 +5,6 @@
 import numpy as np
 import pytest
 from hypothesis import given
-
 from pyscal.constants import EPSILON
 from pyscal.utils import capillarypressure
 
diff --git a/tests/test_utils_interpolation.py b/tests/test_utils_interpolation.py
index 328b24a6..dbfbaf20 100644
--- a/tests/test_utils_interpolation.py
+++ b/tests/test_utils_interpolation.py
@@ -6,7 +6,6 @@
 import pytest
 from hypothesis import given
 from matplotlib import pyplot as plt
-
 from pyscal import GasOil, WaterOil
 from pyscal.constants import EPSILON as epsilon
 from pyscal.utils.interpolation import (
diff --git a/tests/test_utils_monotonicity.py b/tests/test_utils_monotonicity.py
index 14137d67..5219e6c2 100644
--- a/tests/test_utils_monotonicity.py
+++ b/tests/test_utils_monotonicity.py
@@ -4,7 +4,6 @@
 import numpy as np
 import pandas as pd
 import pytest
-
 from pyscal.utils.monotonicity import (
     check_almost_monotone,
     check_limits,
diff --git a/tests/test_utils_relperm.py b/tests/test_utils_relperm.py
index 19495fa3..c4bd047b 100644
--- a/tests/test_utils_relperm.py
+++ b/tests/test_utils_relperm.py
@@ -3,7 +3,6 @@
 import numpy as np
 import pandas as pd
 import pytest
-
 from pyscal.utils.relperm import crosspoint, estimate_diffjumppoint, truncate_zeroness
 
 # pyscal.utils.relperm.crosspoint() is also tested in test_wateroil and test_gasoil.
diff --git a/tests/test_utils_string.py b/tests/test_utils_string.py
index 277e1a4a..16b09d37 100644
--- a/tests/test_utils_string.py
+++ b/tests/test_utils_string.py
@@ -1,7 +1,6 @@
 """Test module for pyscal.utils"""
 
 import pandas as pd
-
 from pyscal.utils.string import comment_formatter, df2str
 
 
diff --git a/tests/test_utils_testing.py b/tests/test_utils_testing.py
index 0fedb1f4..616f2996 100644
--- a/tests/test_utils_testing.py
+++ b/tests/test_utils_testing.py
@@ -4,7 +4,6 @@
 
 import pandas as pd
 import pytest
-
 from pyscal.utils.testing import float_df_checker, sat_table_str_ok
 
 
diff --git a/tests/test_wateroil.py b/tests/test_wateroil.py
index 1a748d12..32fa4bfc 100644
--- a/tests/test_wateroil.py
+++ b/tests/test_wateroil.py
@@ -9,7 +9,6 @@
 import pandas as pd
 import pytest
 from hypothesis import given
-
 from pyscal import WaterOil
 from pyscal.constants import SWINTEGERS
 from pyscal.utils.testing import (
diff --git a/tests/test_wateroil_pc.py b/tests/test_wateroil_pc.py
index 3c90086b..45b968a6 100644
--- a/tests/test_wateroil_pc.py
+++ b/tests/test_wateroil_pc.py
@@ -4,7 +4,6 @@
 import numpy as np
 import pytest
 from hypothesis import given
-
 from pyscal import WaterOil
 from pyscal.constants import MAX_EXPONENT_PC
 from pyscal.utils.testing import check_table, float_df_checker, sat_table_str_ok
diff --git a/tests/test_wateroil_saturation.py b/tests/test_wateroil_saturation.py
index a8bf2180..c5fa743c 100644
--- a/tests/test_wateroil_saturation.py
+++ b/tests/test_wateroil_saturation.py
@@ -4,7 +4,6 @@
 
 import hypothesis.strategies as st
 from hypothesis import given
-
 from pyscal import WaterOil
 from pyscal.constants import EPSILON, SWINTEGERS
 from pyscal.utils.testing import check_table, float_df_checker
diff --git a/tests/test_wateroilgas.py b/tests/test_wateroilgas.py
index 16c30d21..e912158a 100644
--- a/tests/test_wateroilgas.py
+++ b/tests/test_wateroilgas.py
@@ -4,7 +4,6 @@
 from pathlib import Path
 
 import pytest
-
 from pyscal import GasOil, WaterOil, WaterOilGas
 from pyscal.utils.testing import sat_table_str_ok