diff --git a/mlpp_lib/train.py b/mlpp_lib/train.py
index d3846c4..9a28530 100644
--- a/mlpp_lib/train.py
+++ b/mlpp_lib/train.py
@@ -90,7 +90,7 @@ def train(
     res = model.fit(
         x=datamodule.train.x,
         y=datamodule.train.y,
-        sample_weight=datamodule.train.w,
+        sample_weight=(datamodule.train.w,) if datamodule.train.w is not None else None,
         epochs=cfg.get("epochs", 1),
         validation_data=(datamodule.val.x, datamodule.val.y),
         callbacks=callbacks,