diff --git a/kwave/kWaveSimulation.py b/kwave/kWaveSimulation.py
index 7b18ed28..d1da74c2 100644
--- a/kwave/kWaveSimulation.py
+++ b/kwave/kWaveSimulation.py
@@ -1520,7 +1520,7 @@ def _is_binary_sensor_mask(self, kgrid_dim: int) -> bool:
             return True
 
         # If the sensor mask is larger by PML size in each dimension, it's still a binary mask
-        if pml_size := self.options.pml_size is None:
+        if (pml_size := self.options.pml_size) is None:
             return False
 
         if len(pml_size) == 1:
diff --git a/tests/test_kspaceFirstOrder3D_state.py b/tests/test_kspaceFirstOrder3D_state.py
index 3a694957..551574cb 100644
--- a/tests/test_kspaceFirstOrder3D_state.py
+++ b/tests/test_kspaceFirstOrder3D_state.py
@@ -39,7 +39,7 @@ def make_simulation_parameters(directory: Path):
     # define a binary planar sensor
     sensor = kSensor()
     sensor_mask_array = np.zeros(N)
-    sensor_mask_array[0, :, :] = 1  # Corrected to be a plane for 3D
+    sensor_mask_array[0, :, :] = 1 # Corrected to be a plane for 3D
     sensor.mask = sensor_mask_array
 
     input_filename = directory / "kwave_input.h5"
@@ -47,10 +47,10 @@ def make_simulation_parameters(directory: Path):
     checkpoint_filename = directory / "kwave_checkpoint.h5"
 
     simulation_options = SimulationOptions(
-        save_to_disk=True,  # Must be true for kspaceFirstOrder3D
+        save_to_disk=True, # Must be true for kspaceFirstOrder3D
         pml_size=PML_size,
         pml_inside=False,
-        smooth_p0=False,  # p0 is already smoothed
+        smooth_p0=False, # p0 is already smoothed
         data_cast="single",
         input_filename=input_filename,
         output_filename=output_filename,
@@ -75,6 +75,7 @@ def test_kspaceFirstOrder3D_input_state_preservation():
         # Store original states of critical attributes for comparison
         original_source_p0 = deepcopy(source.p0)
         original_sensor_mask = deepcopy(sensor.mask)
+        
 
         # If source.p or source.u were time-varying, store their initial states too.
         # For this test, p0 is the main source attribute.
@@ -122,3 +123,4 @@ def test_kspaceFirstOrder3D_input_state_preservation():
         # Final check that attributes are still the same as the initial state
         assert np.array_equal(source.p0, original_source_p0), "source.p0 was modified after second run"
         assert np.array_equal(sensor.mask, original_sensor_mask), "sensor.mask was modified after second run"
+