diff --git a/.github/workflows/pipeline.yml b/.github/workflows/pipeline.yml
index 4cc51ecd..99593be6 100644
--- a/.github/workflows/pipeline.yml
+++ b/.github/workflows/pipeline.yml
@@ -68,7 +68,7 @@ jobs:
 
       - name: Test
         run: |
-          python -m unittest discover -s tests
+          pytest tests -m "not slow" --durations=0
 
       - name: Install pypa/build
         run: |
diff --git a/pyproject.toml b/pyproject.toml
index 6013bdf7..0083582b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -54,7 +54,6 @@ docs = [
     "sphinx_copybutton>=0.5.1",
     "sphinx-sitemap>=2.5.0",
 ]
-
 ax = [
     "ax-platform >=0.3.5"
 ]
@@ -78,3 +77,9 @@ line-length = 88
 testpaths = [
     "tests",
 ]
+pythonpath = [
+    "tests",
+]
+markers = [
+    "slow: marks tests as slow (deselect with '-m \"not slow\"')",
+]
diff --git a/tests/optimization_problem_fixtures.py b/tests/optimization_problem_fixtures.py
index e8f05683..486f55ea 100644
--- a/tests/optimization_problem_fixtures.py
+++ b/tests/optimization_problem_fixtures.py
@@ -76,6 +76,9 @@ def allow_test_failure_percentage(
 
 
 class TestProblem(OptimizationProblem):
+    # To prevent Pytest interpreting this class as test:
+    __test__ = False
+
     @property
     def optimal_solution(self):
         """Must return X, F, and if it has, G."""
diff --git a/tests/test_binding.py b/tests/test_binding.py
index ae0f9a4f..84b6b471 100644
--- a/tests/test_binding.py
+++ b/tests/test_binding.py
@@ -11,9 +11,6 @@
 
 class Test_Binding(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
 
         component_system = ComponentSystem(2)
diff --git a/tests/test_buffer_capacity.py b/tests/test_buffer_capacity.py
index 3dced6e6..31920447 100644
--- a/tests/test_buffer_capacity.py
+++ b/tests/test_buffer_capacity.py
@@ -11,9 +11,6 @@
 
 class TestBufferCapacity(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         self.components_simple = ComponentSystem(2, charges=[1, 2])
 
diff --git a/tests/test_cache.py b/tests/test_cache.py
index d44da455..16f8fb49 100644
--- a/tests/test_cache.py
+++ b/tests/test_cache.py
@@ -4,8 +4,6 @@
 
 
 class TestCache(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def setUp(self):
         self.cache_dict = ResultsCache(use_diskcache=False)
diff --git a/tests/test_cadet_adapter.py b/tests/test_cadet_adapter.py
index 78df4c9e..7aba6688 100644
--- a/tests/test_cadet_adapter.py
+++ b/tests/test_cadet_adapter.py
@@ -35,9 +35,6 @@ def detect_cadet(install_path: Optional[Path] = None):
 
 class Test_Adapter(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     @unittest.skipIf(found_cadet is False, "Skip if CADET is not installed.")
     def test_check_cadet(self):
         simulator = Cadet(install_path)
@@ -155,6 +152,7 @@ def simulation_results(request: pytest.FixtureRequest):
     return simulation_results
 
 @pytest.mark.parametrize("process", test_cases, indirect=True)
+@pytest.mark.slow
 class TestProcessWithLWE:
 
     def return_process_config(self, process: Process) -> dict:
@@ -566,6 +564,7 @@ def test_sensitivity_config(self, process: Process):
 
 
 @pytest.mark.parametrize("simulation_results", test_cases, indirect=True)
+@pytest.mark.slow
 class TestResultsWithLWE:
     def test_trigger_simulation(self, simulation_results):
         """
diff --git a/tests/test_carousel.py b/tests/test_carousel.py
index 6e643ad9..824507db 100644
--- a/tests/test_carousel.py
+++ b/tests/test_carousel.py
@@ -12,9 +12,6 @@
 
 class Test_Carousel(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         self.component_system = ComponentSystem(2)
 
diff --git a/tests/test_compartment.py b/tests/test_compartment.py
index 62a4074e..ba68bea8 100644
--- a/tests/test_compartment.py
+++ b/tests/test_compartment.py
@@ -9,9 +9,6 @@
 
 class Test_CompartmentBuilder(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         self.component_system = ComponentSystem(2)
 
diff --git a/tests/test_difference.py b/tests/test_difference.py
index 6a61b6d6..9a2cb2c7 100644
--- a/tests/test_difference.py
+++ b/tests/test_difference.py
@@ -40,8 +40,6 @@
 
 from CADETProcess.comparison import SSE
 class TestSSE(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def test_metric(self):
         # Compare with itself
@@ -76,8 +74,6 @@ def test_metric(self):
 
 from CADETProcess.comparison import NRMSE
 class TestNRMSE(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def test_metric(self):
         # Compare with itself
@@ -112,8 +108,6 @@ def test_metric(self):
 
 from CADETProcess.comparison import PeakHeight
 class TestPeakHeight(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def setUp(self):
         # 2 Components, gaussian peaks, constant flow
@@ -202,8 +196,6 @@ def test_metric(self):
 
 from CADETProcess.comparison import PeakPosition
 class TestPeakPosition(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def setUp(self):
         # 2 Components, gaussian peaks, constant flow
@@ -275,8 +267,6 @@ def test_metric(self):
 
 from CADETProcess.comparison import Shape
 class TestShape(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def setUp(self):
         # 2 Components, gaussian peaks, constant flow
@@ -396,8 +386,6 @@ def test_metric(self):
 
 
 class TestFractionation(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def setUp(self):
         fraction_1 = Fraction(
diff --git a/tests/test_equilibrium.py b/tests/test_equilibrium.py
index c1a9b6e8..20ec842f 100644
--- a/tests/test_equilibrium.py
+++ b/tests/test_equilibrium.py
@@ -10,8 +10,6 @@
 
 
 class TestReactionEquilibrium(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def setUp(self):
         component_system = ComponentSystem(2)
@@ -171,8 +169,6 @@ def test_reaction_equilibrium(self):
 
 
 class TestAdsorptionEquilibrium(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def setUp(self):
         component_system_mono = ComponentSystem()
diff --git a/tests/test_events.py b/tests/test_events.py
index 96c1fdcf..ded6eb98 100644
--- a/tests/test_events.py
+++ b/tests/test_events.py
@@ -11,7 +11,7 @@
 Notes
 -----
 Since the EventHandler defines an interface, that requires the
-implementation of some methods, a TestHandler class is defined.
+implementation of some methods, a HandlerFixture class is defined.
 
 Maybe this is too complicated, just use Process instead?
 """
@@ -31,7 +31,8 @@
 plot = True
 
 
-class TestPerformer(Structure):
+class PerformerFixture(Structure):
+
     n_entries = 4
     n_coeff = 4
 
@@ -79,10 +80,11 @@ def section_dependent_parameters(self):
         return parameters
 
 
-class TestHandler(CADETProcess.dynamicEvents.EventHandler):
+class HandlerFixture(CADETProcess.dynamicEvents.EventHandler):
+
     def __init__(self):
         self.name = None
-        self.performer = TestPerformer()
+        self.performer = PerformerFixture()
         super().__init__()
 
     @property
@@ -100,7 +102,7 @@ def parameters(self, parameters):
         except KeyError:
             pass
 
-        super(TestHandler, self.__class__).parameters.fset(self, parameters)
+        super(HandlerFixture, self.__class__).parameters.fset(self, parameters)
 
     @property
     def section_dependent_parameters(self):
@@ -117,11 +119,8 @@ def polynomial_parameters(self):
 
 class Test_Events(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setup_event_handler(self, add_events=False):
-        event_handler = TestHandler()
+        event_handler = HandlerFixture()
         event_handler.cycle_time = 20
 
         if add_events:
diff --git a/tests/test_flow_sheet.py b/tests/test_flow_sheet.py
index 1e19563f..01e8d86e 100644
--- a/tests/test_flow_sheet.py
+++ b/tests/test_flow_sheet.py
@@ -161,9 +161,6 @@ def setup_ssr_flow_sheet(component_system=None):
 class TestFlowSheet(unittest.TestCase):
     """Test general functionatlity of `FlowSheet` class."""
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         self.component_system = ComponentSystem(2)
 
@@ -995,9 +992,6 @@ class TestCstrFlowRate(unittest.TestCase):
     is set, it has properties similar to an `Inlet`.
     """
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         self.component_system = ComponentSystem(2)
 
@@ -1100,8 +1094,6 @@ def test_state_update(self):
         np.testing.assert_almost_equal(cstr_out, cstr_out_expected)
 
 class TestPorts(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def setUp(self):
         self.setup_mct_flow_sheet()
@@ -1561,9 +1553,6 @@ def test_set_output_state(self):
 class TestFlowRateMatrix(unittest.TestCase):
     """Test calculation of flow rates with another simple testcase by @daklauss"""
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         self.component_system = ComponentSystem(1)
 
@@ -1698,8 +1687,6 @@ def test_matrix_example(self):
 
 class TestFlowRateSelfMatrix(unittest.TestCase):
     """Test special case where one unit is connected to itself."""
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def setUp(self):
         self.component_system = ComponentSystem(1)
@@ -1794,9 +1781,6 @@ class TestSingularFlowMatrix(unittest.TestCase):
 
     """
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
 
         self.component_system = ComponentSystem(1)
diff --git a/tests/test_fractions.py b/tests/test_fractions.py
index 46a9c15e..4ed9b21b 100644
--- a/tests/test_fractions.py
+++ b/tests/test_fractions.py
@@ -6,9 +6,6 @@
 
 class Test_Fractions(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def create_fractions(self):
         m_0 = np.array([0, 0])
         frac0 = CADETProcess.fractionation.Fraction(m_0, 1)
diff --git a/tests/test_individual.py b/tests/test_individual.py
index c7696c0b..887f6808 100644
--- a/tests/test_individual.py
+++ b/tests/test_individual.py
@@ -32,9 +32,6 @@ def test_hash_array(self):
 
 
 class TestIndividual(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         x = [1, 2]
         f = [-1]
diff --git a/tests/test_optimization_problem.py b/tests/test_optimization_problem.py
index 452d45d5..c49e6966 100644
--- a/tests/test_optimization_problem.py
+++ b/tests/test_optimization_problem.py
@@ -112,10 +112,6 @@ def min_results_2(cheap_results):
 
 
 class Test_OptimizationVariable(unittest.TestCase):
-
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         self.evaluation_object = EvaluationObject()
 
@@ -330,14 +326,10 @@ def test_transform(self):
             )
 
 
-from tests.test_events import TestHandler
+from tests.test_events import HandlerFixture
 class Test_OptimizationVariableEvents(unittest.TestCase):
-
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
-        evaluation_object = TestHandler()
+        evaluation_object = HandlerFixture()
 
         evt = evaluation_object.add_event(
             'single_index_1D', 'performer.array_1d', 1, indices=0, time=1
@@ -571,7 +563,7 @@ def test_polynomial(self):
 
     def test_multi_eval_obj(self):
         """Test setting indexed variables for multiple evaluation objects."""
-        evaluation_object_2 = TestHandler()
+        evaluation_object_2 = HandlerFixture()
 
         evt = evaluation_object_2.add_event(
             'multi_index_ND', 'performer.ndarray',
@@ -669,9 +661,6 @@ def setup_optimization_problem(
 
 
 class Test_OptimizationProblemSimple(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         optimization_problem = OptimizationProblem('simple', use_diskcache=False)
 
@@ -708,9 +697,6 @@ def test_bounds(self):
 
 
 class Test_OptimizationProblemLinCon(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         optimization_problem = setup_optimization_problem(
             n_lincon=1, use_diskcache=False
@@ -832,9 +818,6 @@ def test_initial_values(self):
 
 
 class Test_OptimizationProblemDepVar(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         optimization_problem = OptimizationProblem('simple', use_diskcache=False)
 
@@ -1007,9 +990,6 @@ def test_initial_values(self):
 
 
 class Test_OptimizationProblemJacobian(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         def single_obj_single_var(x):
             return x[0]**2
@@ -1095,9 +1075,6 @@ class Test_OptimizationProblemConstraintTransforms(unittest.TestCase):
     tests if `A_transformed` and `b_transformed` properties are correctly
     computed.
     """
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setup(self):
         settings.working_directory = './test_problem'
 
@@ -1229,9 +1206,6 @@ class Test_OptimizationProblemEvaluator(unittest.TestCase):
 
     """
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         eval_obj = EvaluationObject()
 
@@ -1309,9 +1283,6 @@ def test_cache(self):
 
 
 class Test_MultiEvaluationObjects(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         eval_obj_1 = EvaluationObject(name='foo')
         eval_obj_2 = EvaluationObject(name='bar')
diff --git a/tests/test_optimization_results.py b/tests/test_optimization_results.py
index 48ba9418..8f616e12 100644
--- a/tests/test_optimization_results.py
+++ b/tests/test_optimization_results.py
@@ -32,9 +32,6 @@ def setup_optimization_results(
 
 
 class TestOptimizationResults(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         self.optimization_results = setup_optimization_results()
 
diff --git a/tests/test_optimizer_behavior.py b/tests/test_optimizer_behavior.py
index acd54301..b0af2265 100644
--- a/tests/test_optimizer_behavior.py
+++ b/tests/test_optimizer_behavior.py
@@ -178,7 +178,7 @@ def optimizer(request):
 
 
 # %% Tests
-
+@pytest.mark.slow
 def test_convergence(optimization_problem: TestProblem, optimizer: OptimizerBase):
     # only test problems that the optimizer can handle. The rest of the tests
     # will be marked as passed
@@ -194,7 +194,7 @@ def test_convergence(optimization_problem: TestProblem, optimizer: OptimizerBase
         else:
             optimization_problem.test_if_solved(results, MOO_TEST_KWARGS)
 
-
+@pytest.mark.slow
 def test_from_initial_values(
     optimization_problem: TestProblem, optimizer: OptimizerBase
 ):
@@ -233,7 +233,7 @@ def __call__(self, results):
             raise RuntimeError("Max number of evaluations reached. Aborting!")
         self.n_calls += 1
 
-
+@pytest.mark.slow
 def test_resume_from_checkpoint(
     optimization_problem: TestProblem, optimizer: OptimizerBase
 ):
diff --git a/tests/test_parallelization_adapter.py b/tests/test_parallelization_adapter.py
index 788057b1..ea594dbd 100644
--- a/tests/test_parallelization_adapter.py
+++ b/tests/test_parallelization_adapter.py
@@ -42,9 +42,6 @@
 class TestParallelizationBackend(unittest.TestCase):
     """Test initializing parallelization backends and n_cores attribute."""
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def test_n_cores(self):
         with self.assertRaises(ValueError):
             sequential_backend = SequentialBackend(n_cores=n_cores)
@@ -89,9 +86,6 @@ class TestParallelEvaluation(unittest.TestCase):
 
     """
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def tearDown(self):
         shutil.rmtree('./tmp', ignore_errors=True)
         shutil.rmtree('./test_parallelization', ignore_errors=True)
@@ -140,9 +134,6 @@ class TestOptimizerParallelizationBackend(unittest.TestCase):
 
     """
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def tearDown(self):
         settings.working_directory = None
 
diff --git a/tests/test_parameters.py b/tests/test_parameters.py
index ab1f6500..3ad8bab8 100755
--- a/tests/test_parameters.py
+++ b/tests/test_parameters.py
@@ -18,9 +18,6 @@
 
 class TestDescription(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         class Model(Structure):
             param_with_description = Integer(description='foo')
@@ -36,8 +33,6 @@ def test_modified_descriptor(self):
 
 
 class TestParameterDictionaries(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def setUp(self):
         class Model(Structure):
@@ -91,9 +86,6 @@ def test_parameters_dict_setter(self):
 
 class TestConstant(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         class Model(Structure):
             const_int = Constant(value=0)
@@ -120,9 +112,6 @@ class NoValue(Structure):
 
 class TestSwitch(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         class Model(Structure):
             switch = Switch(valid=['foo', 'bar'], default='foo')
@@ -146,9 +135,6 @@ class InvalidDefault(Structure):
 
 class TestTyped(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         class Model(Structure):
             string_param = String(default='foo')
@@ -197,9 +183,6 @@ class WrongDefaultType(Structure):
 
 class TestCallable(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         def default_method(x):
             return x
@@ -229,9 +212,6 @@ def test_default(self):
 
 class TestRanged(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         class Model(Structure):
             bound_float_param = RangedFloat(lb=-1, ub=1, default=0)
@@ -264,9 +244,6 @@ class InvalidDefault(Structure):
 
 class TestSizedUnified(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         class Model(Structure):
             sized_list = SizedList(size=4, default=0)
@@ -344,9 +321,6 @@ class InvalidDefaultRange(Structure):
 class TestSizedDependent(unittest.TestCase):
     """Previous test methods for dependently sized parameters."""
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         class Model(Structure):
             dep_1 = UnsignedInteger()
@@ -448,9 +422,6 @@ class InvalidDefault(Structure):
 
 class TestPolynomial(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         class Model(Structure):
             poly_param = Polynomial(n_coeff=2, default=0)
@@ -580,9 +551,6 @@ def test_default(self):
 
 class TestModulated(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         class Model(Structure):
             n_mod = 4
diff --git a/tests/test_population.py b/tests/test_population.py
index 45fa7e66..a15a570e 100644
--- a/tests/test_population.py
+++ b/tests/test_population.py
@@ -22,8 +22,6 @@ def setup_population(n_ind, n_vars, n_obj, n_nonlin=0, n_meta=0, rng=None):
 
 
 class TestPopulation(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def setUp(self):
         x = [1, 2]
@@ -238,8 +236,6 @@ def test_from_dict(self):
 
 
 class TestPareto(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def setUp(self):
         front = ParetoFront(3)
diff --git a/tests/test_process.py b/tests/test_process.py
index c489f4dc..3169aa57 100644
--- a/tests/test_process.py
+++ b/tests/test_process.py
@@ -7,9 +7,6 @@
 
 class Test_process(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def create_process(self):
         return copy.deepcopy(process)
 
diff --git a/tests/test_pymoo.py b/tests/test_pymoo.py
index 5c2f9fbd..cc3428c1 100644
--- a/tests/test_pymoo.py
+++ b/tests/test_pymoo.py
@@ -8,8 +8,6 @@
 
 
 class Test_OptimizationProblemSimple(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def tearDown(self):
         shutil.rmtree('./results_simple', ignore_errors=True)
diff --git a/tests/test_reaction.py b/tests/test_reaction.py
index 4d2b4eac..c8d7d7da 100644
--- a/tests/test_reaction.py
+++ b/tests/test_reaction.py
@@ -13,9 +13,6 @@
 
 class Test_Reaction(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def create_simple_bulk_reaction(self, is_kinetic=True, k_fwd_min=100):
         # 0: NH4+(aq) <=> NH3(aq) + H+(aq)
         component_system = ComponentSystem()
diff --git a/tests/test_sections.py b/tests/test_sections.py
index f2c08b8d..e95d9fad 100644
--- a/tests/test_sections.py
+++ b/tests/test_sections.py
@@ -7,8 +7,6 @@
 
 
 class TestGenerateIndices(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def test_generate_indices(self):
         shape = (3, 3)
@@ -41,8 +39,6 @@ def test_generate_indices(self):
 
 
 class TestSection(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def setUp(self):
         self.constant_section_single = Section(0, 1, 1)
@@ -108,8 +104,6 @@ def test_section_integral(self):
 
 
 class TestTimeLine(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def create_timeline_constant_single(self):
         """Piecewise constant sections with single entry."""
@@ -277,8 +271,6 @@ def test_tl_from_profile(self):
 
 
 class TestMultiTimeLine(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def create_timeline_constant_multi(self):
         """Piecewise constant sections with multiple entries managed by MultiTimeline."""
diff --git a/tests/test_solution.py b/tests/test_solution.py
index deea5f92..5e727b22 100644
--- a/tests/test_solution.py
+++ b/tests/test_solution.py
@@ -91,8 +91,6 @@
 
 
 class TestSolution(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def setUp(self):
         # 2 Components, constant concentration, constant flow
@@ -427,8 +425,6 @@ def test_fraction_mass(self):
 
 
 class TestSliceSolution(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def setUp(self):
         # 2 Components, gaussian peaks, constant flow
@@ -541,9 +537,6 @@ def test_total_concentration(self):
 
 
 class TestPlot(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         # 2 Components, gaussian peaks, constant flow
         self.solution_species = SolutionIO(
diff --git a/tests/test_transform.py b/tests/test_transform.py
index fef00043..3e8f868f 100644
--- a/tests/test_transform.py
+++ b/tests/test_transform.py
@@ -6,8 +6,6 @@
 
 
 class Test_Transform(unittest.TestCase):
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
 
     def test_input_range(self):
         transform = NormLinearTransform(0, 100)
diff --git a/tests/test_unit_operation.py b/tests/test_unit_operation.py
index 936135b6..8d5e2d40 100644
--- a/tests/test_unit_operation.py
+++ b/tests/test_unit_operation.py
@@ -41,9 +41,6 @@
 
 class Test_Unit_Operation(unittest.TestCase):
 
-    def __init__(self, methodName='runTest'):
-        super().__init__(methodName)
-
     def setUp(self):
         self.component_system = ComponentSystem(2)