diff --git a/evaluate.py b/evaluate.py
index 9a4e3ba2b5..42eb064f9b 100644
--- a/evaluate.py
+++ b/evaluate.py
@@ -27,7 +27,7 @@ def evaluate(net, dataloader, device, amp):
                 assert mask_true.min() >= 0 and mask_true.max() <= 1, 'True mask indices should be in [0, 1]'
                 mask_pred = (F.sigmoid(mask_pred) > 0.5).float()
                 # compute the Dice score
-                dice_score += dice_coeff(mask_pred, mask_true, reduce_batch_first=False)
+                dice_score += dice_coeff(mask_pred.squeeze(1), mask_true, reduce_batch_first=False)
             else:
                 assert mask_true.min() >= 0 and mask_true.max() < net.n_classes, 'True mask indices should be in [0, n_classes['
                 # convert to one-hot format