diff --git a/tests/unit/calibration/models/test_polynomial_model.py b/tests/unit/calibration/models/test_polynomial_model.py
index c771f19..9fc7245 100644
--- a/tests/unit/calibration/models/test_polynomial_model.py
+++ b/tests/unit/calibration/models/test_polynomial_model.py
@@ -1,69 +1,59 @@
-import unittest
-from functools import cached_property
-from unittest.mock import patch, ANY
+from unittest.mock import ANY
 
 import numpy as np
+import pytest
 
 from depiction.calibration.models.polynomial_model import PolynomialModel
 
 
-class TestPolynomialModel(unittest.TestCase):
-    def setUp(self) -> None:
-        self.mock_coef = [1, 2, 3]
+@pytest.fixture()
+def mock_coef():
+    return [1, 2, 3]
 
-    @cached_property
-    def mock_model(self):
-        return PolynomialModel(coef=self.mock_coef)
 
-    def test_coef(self) -> None:
-        np.testing.assert_array_equal(
-            np.array([1, 2, 3]),
-            self.mock_model.coef,
-        )
+@pytest.fixture()
+def mock_model(mock_coef):
+    return PolynomialModel(coef=mock_coef)
 
-    def test_is_zero_when_false(self) -> None:
-        self.assertFalse(self.mock_model.is_zero)
 
-    def test_is_zero_when_true(self) -> None:
-        self.assertTrue(PolynomialModel.zero().is_zero)
-        self.mock_coef = [0.0, 0, 0]
-        self.assertTrue(self.mock_model.is_zero)
+def test_coef(mock_model) -> None:
+    np.testing.assert_array_equal(mock_model.coef, np.array([1, 2, 3]))
 
-    def test_degree(self) -> None:
-        self.assertEqual(2, self.mock_model.degree)
 
-    def test_predict(self) -> None:
-        np.testing.assert_array_equal(
-            np.array([6.0, 11]),
-            self.mock_model.predict([1.0, 2]),
-        )
+def test_is_zero_when_false(mock_model) -> None:
+    assert not mock_model.is_zero
 
-    def test_identity(self) -> None:
-        np.testing.assert_array_equal(
-            np.array([0, 1]),
-            PolynomialModel.identity().coef,
-        )
 
-    def test_zero(self) -> None:
-        np.testing.assert_array_equal(
-            np.array([0, 0]),
-            PolynomialModel.zero().coef,
-        )
+def test_is_zero_when_true() -> None:
+    assert PolynomialModel.zero().is_zero
+    assert PolynomialModel([0.0, 0, 0]).is_zero
 
-    @patch("numpy.polyfit")
-    def test_fit_lsq(self, mock_polyfit) -> None:
-        self.mock_model_type = "poly_5"
-        mock_x = np.array([100, 200, 300])
-        mock_y = np.array([1, 2, 3])
-        mock_polyfit.return_value = np.array([5, 7])
 
-        model = PolynomialModel.fit_lsq(mock_x, mock_y, degree=5)
+def test_degree(mock_model) -> None:
+    assert mock_model.degree == 2
 
-        np.testing.assert_array_equal(np.array([5, 7]), model.coef)
-        mock_polyfit.assert_called_once_with(ANY, ANY, deg=5)
-        np.testing.assert_array_equal(mock_x, mock_polyfit.call_args[0][0])
-        np.testing.assert_array_equal(mock_y, mock_polyfit.call_args[0][1])
 
+def test_predict(mock_model) -> None:
+    np.testing.assert_array_equal(mock_model.predict([1.0, 2]), np.array([6.0, 11]))
 
-if __name__ == "__main__":
-    unittest.main()
+
+def test_identity() -> None:
+    np.testing.assert_array_equal(np.array([0, 1]), PolynomialModel.identity().coef)
+
+
+def test_zero() -> None:
+    np.testing.assert_array_equal(np.array([0, 0]), PolynomialModel.zero().coef)
+
+
+def test_fit_lsq(mocker) -> None:
+    mock_polyfit = mocker.patch("numpy.polyfit")
+    mock_x = np.array([100, 200, 300])
+    mock_y = np.array([1, 2, 3])
+    mock_polyfit.return_value = np.array([5, 7])
+
+    model = PolynomialModel.fit_lsq(mock_x, mock_y, degree=5)
+
+    np.testing.assert_array_equal(np.array([5, 7]), model.coef)
+    mock_polyfit.assert_called_once_with(ANY, ANY, deg=5)
+    np.testing.assert_array_equal(mock_x, mock_polyfit.call_args[0][0])
+    np.testing.assert_array_equal(mock_y, mock_polyfit.call_args[0][1])