diff --git a/src/geant4_python_application/files/datasets.py b/src/geant4_python_application/files/datasets.py
index 05ee991..5f5055d 100644
--- a/src/geant4_python_application/files/datasets.py
+++ b/src/geant4_python_application/files/datasets.py
@@ -199,7 +199,9 @@ def install_datasets(show_progress: bool = True):
         return
 
     # check if the datasets are present in the corresponding Geant4 directory
-    if not bool(missing_datasets(os.environ["GEANT4_DATA_DIR"])):
+    if "GEANT4_DATA_DIR" in os.environ and not bool(
+        missing_datasets(os.environ["GEANT4_DATA_DIR"])
+    ):
         # return
         ...
 
diff --git a/tests/test_application.py b/tests/test_application.py
index f43d1f0..8a73463 100644
--- a/tests/test_application.py
+++ b/tests/test_application.py
@@ -54,7 +54,7 @@ def test_seed_single_thread():
             8.09506886e-03,
             1.22345221e00,
         ]
-        energy = np.array(events.track.step.energy[0][0][0:5])
+        energy = np.asarray(events.track.step.energy[0][0][0:5])
         assert np.allclose(energy, reference_value, atol=1e-5)
         assert app.seed == 1100