diff --git a/tardis/plasma/tests/test_complete_plasmas.py b/tardis/plasma/tests/test_complete_plasmas.py
index d90942318e2..31cef61efd9 100644
--- a/tardis/plasma/tests/test_complete_plasmas.py
+++ b/tardis/plasma/tests/test_complete_plasmas.py
@@ -161,7 +161,9 @@ def plasma(self, request, chianti_he_db_fpath, config, tardis_ref_data):
         config["atom_data"] = chianti_he_db_fpath
         sim = Simulation.from_config(config)
         if request.config.getoption("--generate-reference"):
-            sim.plasma.to_hdf(tardis_ref_data, path=config.plasma.save_path, overwrite=True)
+            sim.plasma.to_hdf(
+                tardis_ref_data, path=config.plasma.save_path, overwrite=True
+            )
             pytest.skip("Reference data saved at {0}".format(tardis_ref_data))
         return sim.plasma
 
diff --git a/tardis/simulation/tests/test_simulation.py b/tardis/simulation/tests/test_simulation.py
index 8f9f889e99d..9c473ccabd7 100644
--- a/tardis/simulation/tests/test_simulation.py
+++ b/tardis/simulation/tests/test_simulation.py
@@ -53,9 +53,15 @@ def simulation_one_loop(
             "output_nu",
             "output_energy",
         ]
-        simulation.to_hdf(tardis_ref_data, "", "test_simulation", overwrite=True)
-        simulation.model.to_hdf(tardis_ref_data, "", "test_simulation", overwrite=True)
-        simulation.runner.to_hdf(tardis_ref_data, "", "test_simulation", overwrite=True)
+        simulation.to_hdf(
+            tardis_ref_data, "", "test_simulation", overwrite=True
+        )
+        simulation.model.to_hdf(
+            tardis_ref_data, "", "test_simulation", overwrite=True
+        )
+        simulation.runner.to_hdf(
+            tardis_ref_data, "", "test_simulation", overwrite=True
+        )
         pytest.skip("Reference data was generated during this run.")
 
 
diff --git a/tardis/tests/test_tardis_full.py b/tardis/tests/test_tardis_full.py
index 8666679df2a..2c42d74f414 100644
--- a/tardis/tests/test_tardis_full.py
+++ b/tardis/tests/test_tardis_full.py
@@ -34,7 +34,9 @@ def runner(self, atomic_data_fname, tardis_ref_data, generate_reference):
                 "spectrum",
                 "spectrum_virtual",
             ]
-            simulation.runner.to_hdf(tardis_ref_data, "", self.name, overwrite=True)
+            simulation.runner.to_hdf(
+                tardis_ref_data, "", self.name, overwrite=True
+            )
             pytest.skip("Reference data was generated during this run.")
 
     @pytest.fixture(scope="class")