diff --git a/evaluate.py b/evaluate.py
index 88b337b..7db882d 100644
--- a/evaluate.py
+++ b/evaluate.py
@@ -24,12 +24,12 @@ def evaluate(net, dataloader, device):
 
             # convert to one-hot format
             if net.n_classes == 1:
-                mask_pred = (F.sigmoid(mask_pred) > 0).float()
+                mask_pred = (F.sigmoid(mask_pred) > 0.5).float()
             else:
                 mask_pred = F.one_hot(mask_pred.argmax(dim=1), net.n_classes).permute(0, 3, 1, 2).float()
 
             # compute the Dice score, ignoring background
-            dice_score += multiclass_dice_coeff(mask_pred[:, :1, ...], mask_true[:, :1, ...], reduce_batch_first=False)
+            dice_score += multiclass_dice_coeff(mask_pred[:, 1:, ...], mask_true[:, 1:, ...], reduce_batch_first=False)
 
     net.train()
     return dice_score / num_val_batches