diff --git a/verl/workers/actor/megatron_actor.py b/verl/workers/actor/megatron_actor.py
index ce52956d042..abff9e1690c 100644
--- a/verl/workers/actor/megatron_actor.py
+++ b/verl/workers/actor/megatron_actor.py
@@ -530,9 +530,17 @@ def logits_processor(logits, label, label_mask):
                     assert label.shape == label_mask.shape
                     ret = {}
                     if calculate_entropy:
+                        logits_bak = logits.clone()
+                        logger.warning_once(
+                            "For memory-efficient computation, enable fused kernels via "
+                            "`actor_rollout_ref.model.use_fused_kernels=True`. "
+                            "The current `clone()` operation ensures correctness but increases memory usage."
+                        )
                         entropy = vocab_parallel_entropy(logits)
                         ret["entropy"] = entropy
-                    log_probs = vocab_parallel_log_probs_from_logits(logits, label)
+                    else:
+                        logits_bak = logits
+                    log_probs = vocab_parallel_log_probs_from_logits(logits_bak, label)
                     log_probs = log_probs.masked_fill(~label_mask, 0.0)
                     ret["log_probs"] = log_probs
                     return ret