diff --git a/torch_xla/distributed/zero_redundancy_optimizer.py b/torch_xla/distributed/zero_redundancy_optimizer.py
index 337e154bf30..f00929eeb86 100644
--- a/torch_xla/distributed/zero_redundancy_optimizer.py
+++ b/torch_xla/distributed/zero_redundancy_optimizer.py
@@ -91,7 +91,9 @@ def init_zero(self):
           group = list(group)
         self.local_rank = group.index(self.global_rank)
     if self.local_rank is None:
-      raise ValueError(f"Current rank {self.global_rank} is missing from the sharding_groups {self.sharding_groups}")
+      raise ValueError(
+          f"Current rank {self.global_rank} is missing from the sharding_groups {self.sharding_groups}"
+      )
     # Shard parameters for use in optimizer
     sharded_param_groups = self._shard_parameters()
     # Optimizer initialization