diff --git a/src/vampy/automatedPreprocessing/visualize.py b/src/vampy/automatedPreprocessing/visualize.py
index 1988ec0e..92c6466e 100644
--- a/src/vampy/automatedPreprocessing/visualize.py
+++ b/src/vampy/automatedPreprocessing/visualize.py
@@ -5,7 +5,7 @@
 version = vtk.vtkVersion().GetVTKMajorVersion()
 
 
-def visualize_model(network_elements, probe_points, output_surface, mean_inflow_rate):
+def visualize_model(network_elements, probe_points, output_surface, mean_inflow_rate):  # pragma: no cover
     """
     Visualize surface model / mesh with distributed flow rates at each inlet/outlet
     in an interactive VTK window.
diff --git a/tests/test_pre_processing.py b/tests/test_pre_processing.py
index d21f5b32..416f88d4 100644
--- a/tests/test_pre_processing.py
+++ b/tests/test_pre_processing.py
@@ -15,7 +15,7 @@ def test_mesh_model_with_one_inlet():
                              smoothing_method="taubin",
                              refine_region=False,
                              coarsening_factor=1.3,
-                             visualize=False,
+                             visualize=True,
                              compress_mesh=False,
                              outlet_flow_extension_length=1,
                              inlet_flow_extension_length=1