diff --git a/utils/criterion.py b/utils/criterion.py
index 37bd7036..0081c9c9 100644
--- a/utils/criterion.py
+++ b/utils/criterion.py
@@ -70,7 +70,10 @@ def _ohem_forward(self, score, target, **kwargs):
         tmp_target[tmp_target == self.ignore_label] = 0
         pred = pred.gather(1, tmp_target.unsqueeze(1))
         pred, ind = pred.contiguous().view(-1,)[mask].contiguous().sort()
-        min_value = pred[min(self.min_kept, pred.numel() - 1)]
+        if pred.numel() > 0:
+            min_value = pred[min(self.min_kept, pred.numel() - 1)]
+        else:
+            return score.new_tensor(0.0)
         threshold = max(min_value, self.thresh)
 
         pixel_losses = pixel_losses[mask][ind]