diff --git a/solo/utils/checkpointer.py b/solo/utils/checkpointer.py
index 02ce4109..7d9b113c 100644
--- a/solo/utils/checkpointer.py
+++ b/solo/utils/checkpointer.py
@@ -174,8 +174,7 @@ def on_train_epoch_end(self, trainer: pl.Trainer, _):
         if epoch % self.frequency == 0:
             self.save(trainer)
 
-    def on_train_end(self, trainer: pl.
-Trainer, _):
+    def on_train_end(self, trainer: pl.Trainer, _):
         """Saves model at the end of training.
 
         Args: