diff --git a/src/lightning_trainable/trainable/trainable.py b/src/lightning_trainable/trainable/trainable.py
index fc094e4..9684043 100644
--- a/src/lightning_trainable/trainable/trainable.py
+++ b/src/lightning_trainable/trainable/trainable.py
@@ -269,7 +269,7 @@ def fit(self, logger_kwargs: dict = None, trainer_kwargs: dict = None, fit_kwarg
         return {
             key: value.item()
             for key, value in trainer.callback_metrics.items()
-            if any(key.startswith(key) for key in ["training/", "validation/"])
+            if any(key.startswith(k) for k in ["training/", "validation/"])
         }
 
     @torch.enable_grad()