diff --git a/pytorch_lightning/metrics/functional/classification.py b/pytorch_lightning/metrics/functional/classification.py
index 83b27a7ab2d53..0a77dd6b67682 100644
--- a/pytorch_lightning/metrics/functional/classification.py
+++ b/pytorch_lightning/metrics/functional/classification.py
@@ -181,9 +181,9 @@ def stat_scores_multiple_classes(
     num_classes = get_num_classes(pred=pred, target=target, num_classes=num_classes)
 
     if pred.dtype != torch.bool:
-        pred.clamp_max_(max=num_classes)
+        pred = pred.clamp_max(max=num_classes)
     if target.dtype != torch.bool:
-        target.clamp_max_(max=num_classes)
+        target = target.clamp_max(max=num_classes)
 
     possible_reductions = ('none', 'sum', 'elementwise_mean')
     if reduction not in possible_reductions: