diff --git a/torchrl/envs/env_creator.py b/torchrl/envs/env_creator.py
index cfe2d36101c..caa2d759a8b 100644
--- a/torchrl/envs/env_creator.py
+++ b/torchrl/envs/env_creator.py
@@ -8,6 +8,7 @@
 from collections import OrderedDict
 from collections.abc import Callable
 from multiprocessing.sharedctypes import Synchronized
+from multiprocessing.synchronize import Lock, RLock
 
 import torch
 from tensordict import TensorDictBase
@@ -141,8 +142,12 @@ def meta_data(self, value: EnvMetaData):
 
     @staticmethod
     def _is_mp_value(val):
-
-        return isinstance(val, (Synchronized,)) and hasattr(val, "_obj")
+        if isinstance(val, (Synchronized,)) and hasattr(val, "_obj"):
+            return True
+        # Also check for lock types which need to be shared across processes
+        if isinstance(val, (Lock, RLock)):
+            return True
+        return False
 
     @classmethod
     def _find_mp_values(cls, env_or_transform, values, prefix=()):