diff --git a/torchrl/envs/common.py b/torchrl/envs/common.py
index 13d02af2b36..a563f60837d 100644
--- a/torchrl/envs/common.py
+++ b/torchrl/envs/common.py
@@ -3266,7 +3266,7 @@ def maybe_reset(self, tensordict: TensorDictBase) -> TensorDictBase:
         """
         if self._simple_done:
             done = tensordict._get_str("done", default=None)
-            any_done = done.any()
+            any_done = done is not None and done.any()
             if any_done:
                 tensordict._set_str(
                     "_reset",