diff --git a/src/icosagon/data.py b/src/icosagon/data.py
index b04432e..0690d29 100644
--- a/src/icosagon/data.py
+++ b/src/icosagon/data.py
@@ -31,6 +31,9 @@ def _equal(x: torch.Tensor, y: torch.Tensor):
     indices_y = list(map(tuple, y.indices().transpose(0, 1)))
     order_y = sorted(range(len(indices_y)), key=lambda idx: indices_y[idx])
 
+    if not indices_x == indices_y:
+        return torch.tensor(0, dtype=torch.uint8)
+
     return (x.values()[order_x] == y.values()[order_y])