diff --git a/apax/config/common.py b/apax/config/common.py
index c2acaf5a..393dfdb4 100644
--- a/apax/config/common.py
+++ b/apax/config/common.py
@@ -32,8 +32,7 @@ def parse_config(config: Union[str, os.PathLike, dict], mode: str = "train") ->
 
 
 def flatten(dictionary, parent_key="", separator="_"):
-    """https://stackoverflow.com/questions/6027558/flatten-nested-dictionaries-compressing-keys
-    """
+    """https://stackoverflow.com/questions/6027558/flatten-nested-dictionaries-compressing-keys"""
     items = []
     for key, value in dictionary.items():
         new_key = parent_key + separator + key if parent_key else key
diff --git a/apax/train/trainer.py b/apax/train/trainer.py
index 6d6bc0f0..8c040a3f 100644
--- a/apax/train/trainer.py
+++ b/apax/train/trainer.py
@@ -107,12 +107,10 @@ def fit(
             epoch_loss["val_loss"] /= val_steps_per_epoch
             epoch_loss["val_loss"] = float(epoch_loss["val_loss"])
 
-            epoch_metrics.update(
-                {
-                    f"val_{key}": float(val)
-                    for key, val in val_batch_metrics.compute().items()
-                }
-            )
+            epoch_metrics.update({
+                f"val_{key}": float(val)
+                for key, val in val_batch_metrics.compute().items()
+            })
 
         epoch_metrics.update({**epoch_loss})