diff --git a/mu_map/training/lib.py b/mu_map/training/lib.py
index 8b27afbe4031752cb9718e1502de34f5e4d624db..c7b5cc446106754f9770f093de45311da82f062f 100644
--- a/mu_map/training/lib.py
+++ b/mu_map/training/lib.py
@@ -71,7 +71,7 @@ class AbstractTraining:
         snapshot_dir: str,
         snapshot_epoch: int,
         early_stopping: Optional[int] = None,
-        logger: Optional[Logger],
+        logger: Optional[Logger] = None,
     ):
         self.epochs = epochs
         self.batch_size = batch_size