diff --git a/tests/icosagon/test_batch.py b/tests/icosagon/test_batch.py
index b6cd6d6..b5882db 100644
--- a/tests/icosagon/test_batch.py
+++ b/tests/icosagon/test_batch.py
@@ -92,6 +92,27 @@ def test_flatten_predictions_04():
         pred_flat = flatten_predictions(pred, part_type='x')
 
 
+def test_flatten_predictions_05():
+    x = torch.rand(5000)
+    y = torch.cat([ x, x ])
+    z = torch.cat([ torch.ones(5000), torch.zeros(5000) ])
+
+    rel_pred = RelationPredictions(
+        TrainValTest(x, torch.zeros(0), torch.zeros(0)),
+        TrainValTest(x, torch.zeros(0), torch.zeros(0)),
+        TrainValTest(torch.zeros(0), torch.zeros(0), torch.zeros(0)),
+        TrainValTest(torch.zeros(0), torch.zeros(0), torch.zeros(0))
+    )
+    fam_pred = RelationFamilyPredictions([ rel_pred ])
+    pred = Predictions([ fam_pred ])
+
+    for _ in range(10):
+        pred_flat = flatten_predictions(pred, part_type='train')
+        assert torch.all(pred_flat.predictions == y)
+        assert torch.all(pred_flat.truth == z)
+        assert pred_flat.part_type == 'train'
+
+
 def test_batch_indices_01():
     indices = BatchIndices(torch.tensor([0, 1, 2, 3, 4]), 'train')
     assert torch.all(indices.indices == torch.tensor([0, 1, 2, 3, 4]))