diff --git a/napari_clusters_plotter/_tests/test_plotter.py b/napari_clusters_plotter/_tests/test_plotter.py
index 6b2a5bb6..9c12edb4 100644
--- a/napari_clusters_plotter/_tests/test_plotter.py
+++ b/napari_clusters_plotter/_tests/test_plotter.py
@@ -141,7 +141,7 @@ def test_plotter_on_labels2d_timelapse(make_napari_viewer):
     data_2d_timelapse = np.expand_dims(
         data_2d_timelapse, axis=1
     )  # add unidimensional z axis
-    assert len(data_2d_timelapse) == 4
+    assert len(data_2d_timelapse.shape) == 4
     # Create some random features
     label_column = np.tile(np.arange(1, n_labels + 1), n_timepoints)
     feature1 = np.random.normal(size=n_labels * n_timepoints)
@@ -200,7 +200,7 @@ def test_plotter_on_labels3d_timelapse(make_napari_viewer):
             for t in range(n_timepoints)
         ]
     )
-    assert len(data_3d_timelapse) == 4
+    assert len(data_3d_timelapse.shape) == 4
     # Create some random features
     label_column = np.tile(np.arange(1, n_labels + 1), n_timepoints)
     feature1 = np.random.normal(size=n_labels * n_timepoints)