diff --git a/src/graphnet/data/dataset/dataset.py b/src/graphnet/data/dataset/dataset.py
index c1f785bc9..d6fe1d019 100644
--- a/src/graphnet/data/dataset/dataset.py
+++ b/src/graphnet/data/dataset/dataset.py
@@ -369,7 +369,7 @@ def _post_init(self) -> None:
 
     @abstractmethod
     def _get_all_indices(self) -> List[int]:
-        """Return a list of all available values in `self._index_column`."""
+        """Return a list of all unique values in `self._index_column`."""
 
     @abstractmethod
     def _get_event_index(