diff --git a/plantseg/core/zoo.py b/plantseg/core/zoo.py
index 9e1699fc..2e0bffb6 100644
--- a/plantseg/core/zoo.py
+++ b/plantseg/core/zoo.py
@@ -342,7 +342,7 @@ def get_model_by_id(self, model_id: str):
         https://bioimage-io.github.io/collection-bioimage-io/rdfs/10.5281/zenodo.8401064/8429203/rdf.yaml
         """
 
-        if not self.models_bioimageio:
+        if not hasattr(self, 'models_bioimageio'):
             self.refresh_bioimageio_zoo_urls()
 
         if model_id not in self.models_bioimageio.index:
@@ -458,13 +458,13 @@ def _is_plantseg_model(self, collection_entry: dict) -> bool:
 
     def get_bioimageio_zoo_plantseg_model_names(self) -> list[str]:
         """Return a list of model names in the BioImage.IO Model Zoo tagged with 'plantseg'."""
-        if not self.models_bioimageio:
+        if not hasattr(self, 'models_bioimageio'):
             self.refresh_bioimageio_zoo_urls()
         return sorted(model_zoo.models_bioimageio[model_zoo.models_bioimageio["supported"]].index.to_list())
 
     def get_bioimageio_zoo_all_model_names(self) -> list[str]:
         """Return a list of all model names in the BioImage.IO Model Zoo."""
-        if not self.models_bioimageio:
+        if not hasattr(self, 'models_bioimageio'):
             self.refresh_bioimageio_zoo_urls()
         return sorted(model_zoo.models_bioimageio.index.to_list())
 
diff --git a/tests/core/test_zoo.py b/tests/core/test_zoo.py
index 2e0788a2..8a1b92f5 100644
--- a/tests/core/test_zoo.py
+++ b/tests/core/test_zoo.py
@@ -47,6 +47,8 @@ def test_model_output_normalisation(self, model_name):
 class TestBioImageIOModelZoo:
     """Test the BioImage.IO model zoo"""
 
+    model_zoo.refresh_bioimageio_zoo_urls()
+
     @pytest.mark.parametrize("model_id", MODEL_IDS)
     def test_get_model_by_id(self, model_id):
         """Try to load a model from the BioImage.IO model zoo by ID."""
@@ -62,9 +64,3 @@ def test_halo_computation_for_bioimageio_model(self, model_id):
         model, _, _ = model_zoo.get_model_by_id(model_id)
         halo = model_zoo.compute_halo(model)
         assert halo == 44
-
-    def test_models_bioimageio(self):
-        """`model_zoo` has no `models_bioimageio` attribute until `.refresh_bioimageio_zoo_urls()` is called."""
-        assert not hasattr(model_zoo, 'models_bioimageio')
-        model_zoo.refresh_bioimageio_zoo_urls()
-        assert hasattr(model_zoo, 'models_bioimageio')