diff --git a/torchrl/envs/common.py b/torchrl/envs/common.py
index 5544e48c0bb..5a4698346aa 100644
--- a/torchrl/envs/common.py
+++ b/torchrl/envs/common.py
@@ -379,6 +379,10 @@ class EnvBase(nn.Module, metaclass=_EnvPostInit):
         _skip_maybe_reset (bool): if ``True``, :meth:`step_and_maybe_reset` will skip calling
             :meth:`maybe_reset` after each step. This is useful for auto-resetting environments
             that already handle resets inside their :meth:`_step` method. Defaults to ``False``.
+        _trust_step_output (bool): if ``True``, :meth:`step` will skip the :meth:`_step_proc_data`
+            validation (reward shape checks, done-key completion, type checks) after :meth:`_step`.
+            Set this when the environment guarantees that its :meth:`_step` output always has correct
+            shapes, all done keys present, and proper dtypes. Defaults to ``False``.
 
     Methods:
         step (TensorDictBase -> TensorDictBase): step in the environment
@@ -481,6 +485,7 @@ class EnvBase(nn.Module, metaclass=_EnvPostInit):
     _device: torch.device | None
     _is_spec_locked: bool = False
     _skip_maybe_reset: bool = False
+    _trust_step_output: bool = False
 
     def __init__(
         self,
@@ -2245,7 +2250,8 @@ def step(self, tensordict: TensorDictBase) -> TensorDictBase:
 
         if next_tensordict is None:
             next_tensordict = self._step(tensordict)
-            next_tensordict = self._step_proc_data(next_tensordict)
+            if not self._trust_step_output:
+                next_tensordict = self._step_proc_data(next_tensordict)
         if next_preset is not None:
             # tensordict could already have a "next" key
             # this could be done more efficiently by not excluding but just passing
diff --git a/torchrl/envs/transforms/transforms.py b/torchrl/envs/transforms/transforms.py
index 5a4fc241169..1502fd158c4 100644
--- a/torchrl/envs/transforms/transforms.py
+++ b/torchrl/envs/transforms/transforms.py
@@ -1263,8 +1263,10 @@ def _step(self, tensordict: TensorDictBase) -> TensorDictBase:
                 next_tensordict.update(
                     next_preset.exclude(*next_tensordict.keys(True, True))
                 )
-            self.base_env._complete_done(self.base_env.full_done_spec, next_tensordict)
-            # we want the input entries to remain unchanged
+            if not self.base_env._trust_step_output:
+                self.base_env._complete_done(
+                    self.base_env.full_done_spec, next_tensordict
+                )
             next_tensordict = self.transform._step(tensordict_in, next_tensordict)
 
         if partial_steps is not None: