diff --git a/llms/mlx_lm/tuner/datasets.py b/llms/mlx_lm/tuner/datasets.py
index f1345634..c8b39e31 100644
--- a/llms/mlx_lm/tuner/datasets.py
+++ b/llms/mlx_lm/tuner/datasets.py
@@ -116,7 +116,7 @@ class CompletionsDatasetCollection:
 
     def get_prompt_and_completion(self, idx: int):
         def getitem(dataset: CompletionsDataset, index: int):
-            dataset.get_prompt_and_completion(index)
+            return dataset.get_prompt_and_completion(index)
 
         return self.__fetch_and_process_item__(idx, getitem)