diff --git a/egs/libriheavy/LM/zipformer1/train.py b/egs/libriheavy/LM/zipformer1/train.py
index fddf6e59d..903586e8e 100755
--- a/egs/libriheavy/LM/zipformer1/train.py
+++ b/egs/libriheavy/LM/zipformer1/train.py
@@ -953,7 +953,8 @@ def run(rank, world_size, args):
     model.to(device)
     if world_size > 1:
         logging.info("Using DDP")
-        model = DDP(model, device_ids=[rank])
+        model = DDP(model, device_ids=[rank],
+                    find_unused_parameters=True)
 
     optimizer = ScaledAdam(
         get_parameter_groups_with_lrs(