diff --git a/moojoco/environment/mjc_env.py b/moojoco/environment/mjc_env.py
index a710ab0..7c2a889 100644
--- a/moojoco/environment/mjc_env.py
+++ b/moojoco/environment/mjc_env.py
@@ -277,7 +277,11 @@ def reset(
         self, rng: List[np.random.RandomState], *args, **kwargs
     ) -> VectorMJCEnvState:
         self._states = list(
-            self._pool.map(lambda env, sub_rng: env.reset(sub_rng, *args, **kwargs), self._envs, rng)
+            self._pool.map(
+                lambda env, sub_rng: env.reset(sub_rng, *args, **kwargs),
+                self._envs,
+                rng,
+            )
         )
 
         return self._merged_states