diff --git a/tensordict/tensorclass.py b/tensordict/tensorclass.py
index 06be65580..fdd5d4b83 100644
--- a/tensordict/tensorclass.py
+++ b/tensordict/tensorclass.py
@@ -936,6 +936,9 @@ def wrapper(
             batch_size = torch.Size(())
         else:
             batch_size = kwargs.pop("batch_size", torch.Size(()))
+        if batch_size is None:
+            batch_size = torch.Size(())
+
         if "names" in required_params:
             names = None
         else: