diff --git a/src/datasets/arrow_dataset.py b/src/datasets/arrow_dataset.py
index 1fc45e775fa..a75a30565d9 100644
--- a/src/datasets/arrow_dataset.py
+++ b/src/datasets/arrow_dataset.py
@@ -2258,7 +2258,7 @@ def validate_function_output(processed_inputs, indices):
                 )
                 if all_dict_values_are_lists is False:
                     raise TypeError(
-                        "Provided `function` which is applied to all elements of table returns a `dict` of types {[type(x) for x in processed_inputs.values()]}. When using `batched=True`, make sure provided `function` returns a `dict` of types like `{allowed_batch_return_types}`."
+                        f"Provided `function` which is applied to all elements of table returns a `dict` of types {[type(x) for x in processed_inputs.values()]}. When using `batched=True`, make sure provided `function` returns a `dict` of types like `{allowed_batch_return_types}`."
                     )
 
         def apply_function_on_filtered_inputs(inputs, indices, check_same_num_examples=False, offset=0):