diff --git a/src/gflownet/algo/trajectory_balance.py b/src/gflownet/algo/trajectory_balance.py
index fcd171b4..5e7e01be 100644
--- a/src/gflownet/algo/trajectory_balance.py
+++ b/src/gflownet/algo/trajectory_balance.py
@@ -342,7 +342,10 @@ def construct_batch(self, trajs, cond_info, log_rewards):
         return batch
 
     def compute_batch_losses(
-        self, model: TrajectoryBalanceModel, batch: gd.Batch, num_bootstrap: int = 0  # type: ignore[override]
+        self,
+        model: TrajectoryBalanceModel,
+        batch: gd.Batch,
+        num_bootstrap: int = 0,  # type: ignore[override]
     ):
         """Compute the losses over trajectories contained in the batch
 
diff --git a/src/gflownet/data/qm9.py b/src/gflownet/data/qm9.py
index f35bdb14..8fd144c2 100644
--- a/src/gflownet/data/qm9.py
+++ b/src/gflownet/data/qm9.py
@@ -14,7 +14,6 @@
 class QM9Dataset(Dataset):
     def __init__(self, h5_file=None, xyz_file=None, train=True, targets=["gap"], split_seed=142857, ratio=0.9):
         if h5_file is not None:
-
             self.hdf = pd.HDFStore(h5_file, "r")
             self.df = self.hdf["df"]
             self.is_hdf = True